The Lost World of Aquaterra

Illustrations by Owen Pomery

Imagine a planet that’s home not only to the seven continents you know but also to an immense feature you’ve never heard of, continental in scale. Extending along the world’s coastal shelves from the tropics almost to the poles, this place is roughly equivalent in size to South America, with a total area of more than 6.6 million square miles. During the last Ice Age, it consisted almost entirely of lowland ecosystems: cold grasslands and tundras in the far north, grazed by woolly mammoths and steppe bison; temperate woodlands and open country in the middle latitudes, home to aurochs, horses, and giant elk; tropical forests, grasslands, and mangrove swamps near the equator, inhabited by Stegodons, Asian hippos, and Komodo dragons; and dry scrub in the far south, roamed by marsupial lions, giant flightless birds, and lizards the size of crocodiles. Great rivers, fed by an abundance of lakes and smaller streams, cut their way through many of these lowlands, eventually opening out into marshes, lagoons, estuaries, and tidal flats as they approached the coast.

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Imagine that human beings settled this place after migrating out of Africa. As they dispersed, they developed technologies and vessels that allowed them to travel by sea; they devised hunting and fishing techniques that allowed them to accumulate surpluses of food and establish small permanent settlements; they buried their dead, built monumental structures, and organized themselves into social hierarchies. It may have been here, in fact—millennia before the rise of ancient Mesopotamia and Egypt—that many of the developments we associate with “civilization” first occurred. But then imagine this: Some 20,000 years ago, these lands began to flood, and by 6,000 years ago, they had disappeared entirely, taking with them much of the story of our past.

As it happens, there really is such a place. You’ve almost certainly been there yourself. It has even been given a name—and, no, it’s not Atlantis. It’s Aquaterra.

I first learned about Aquaterra more than a decade ago, when I received an email from the person who came up with the name—Jerome E. Dobson, a professor emeritus of geography at the University of Kansas and president emeritus of the American Geographical Society. Dobson had read a book I’d written called The Fourth Part of the World, which tells the story of a small team of Renaissance cartographers who, in 1507, became some of the first to map the giant landmass that European sailors had begun to explore across the Atlantic. To honor Amerigo Vespucci, who they believed had been the first to reach this “new” land, these cartographers had called the place America.

[From the January/February 2007 issue: Toby Lester on the town that gave America its name]

Dobson told me another giant “new” landmass was coming into view that deserved to be put on the map. If I wanted to learn more, he said, I should read “Aquaterra Incognita,” a 2014 paper he’d published in the journal Geographical Review.

It’s a fascinating monograph. To understand where—and what—Aquaterra is, Dobson writes, you have to think about how sea levels fall and rise during an ice age. As the planet cools, ocean water becomes locked up in continental ice sheets, and sea levels fall by hundreds of feet. Eventually the planet starts warming again, the ice melts, and sea levels rise once more. During the past million years or so, this cycle has repeated itself many times. Today we’re living through an “interglacial,” a relatively brief warm period during which the ice sheets have retreated and sea levels are unusually high.

If you were able to speed up the glacial cycle and watch it from space, you’d observe the ebb and flow of a planetary tide—one that over the course of millennia alternately exposes and submerges immense expanses of land along the continental shelves. The result, as Dobson writes, is “a vast earth feature,” bounded by the highest and lowest sea levels of the glacial cycle, that “transforms back and forth among upland, wetland, and seafloor.” This Earth feature is what he calls Aquaterra.

For much of the most recent glacial cycle, Aquaterra was mainly terra, but today it’s mostly aqua. If you’ve swum or boated near almost any coastline, you’ve been there. Aquaterra isn’t just the land now underwater; it’s the whole zone that the glacial cycles have alternately drowned and exposed. That includes many of today’s beaches and coastal lowlands, which were underwater during warmer periods in the past and, as we’re now learning the hard way, are flooding again as global temperatures rise. The present-day seafloor of Aquaterra, Dobson argues, is the “least-known zone on earth”—less mapped than the floor of the deep ocean (or even the surfaces of Mars, Venus, and the moon).

[From the October 2021 issue: Did the first Americans arrive by land or by sea?]

When modern human beings began to move out of Africa in serious numbers, starting at least 70,000 years ago, the planet had already been cooling for some 45,000 years, and sea levels were already more than 200 feet below where they are now. During the following 50,000 years, sea levels continued to drop, which meant that as people spread across the globe, they were often moving through and settling in coastal regions of Aquaterra that are now as much as 400 feet underwater. And for much of that time, they were doing far more than just hunting and gathering. Many of the developments that have defined modern human society, Dobson argues, may have had their origins in those now-submerged lands. “Compare the most recent curve of sea level rise against the timeline of cultural innovations,” he writes, “and you will find that much human progress occurred while seacoasts were still quite low.” Aquaterra therefore demands recognition—and exploration.

“It was not just a place,” Dobson told me. “It was a wellspring of the human race.”

Dobson has long been on something of a lonely quest to get geographers to adopt the name Aquaterra. The chance to name a giant new Earth feature doesn’t arrive often (Antarctica, one of the most recent additions, began to appear on maps in the 1880s, although the word had been around for centuries), and if that feature happens to be largely invisible, you’re likely to run into difficulties persuading others to go along with your name. Call the feature what you will, but it exists: During the past 20,000 years, huge stretches of formerly inhabited land along the world’s coastal shelves have disappeared underwater, taking with them tens of thousands of years of human history.

Until recently, that is. During the past few decades, artifacts and sites dating back millennia have been found off the coasts of every inhabited continent. A growing number of researchers—geographers, archaeologists, anthropologists, amateur enthusiasts—are turning their attention to what lies offshore. “Everywhere we’ve systematically looked, we’ve found some areas where the former landscape has survived,” Jessi Halligan, an anthropologist at Texas A&M, told me. “And in a lot of those places, those former landscapes have had sites on them.”

Illustration by Owen Pomery. Source: Vince Gaffney.Taken together, the lands that make up Aquaterra, in orange, amount to a mass the size of South America.

The sheer range of these underwater finds is remarkable. Hand axes that are 300,000 to 1.4 million years old have turned up in the waters off South Africa. Neanderthal artifacts dating back more than 200,000 years have been found under the North Sea. In 2014 and 2015, a dredging project in Indonesia’s Madura Strait brought up a rich trove of fossils that are 120,000 to 160,000 years old, including the remains of early hominins and a host of megafaunal species.

The finds that bear most directly on the modern human story, however, come from the most recent glacial cycle. In the Mediterranean, near Marseille, France, there’s Cosquer Cave, whose entrance, 120 feet below sea level, offers divers access to dry interior chambers adorned with engravings and wall paintings that date from 19,000 to 27,000 years ago. In the Baltic, near Germany, there’s the recently discovered Blinkerwall, one of Europe’s oldest and largest Stone Age structures—more than 10,000 years old and more than half a mile long—which seems to have been used as a drive lane for hunting reindeer. Off the southern coast of England, at Bouldnor Cliff, near the Isle of Wight, divers have discovered roughly 1,000 stone tools and a wealth of organic material, preserved by lack of oxygen, including fragments of worked wood, traces of food, and the oldest pieces of string ever found in Britain.

There’s action across the Atlantic too. Fishermen in the Chesapeake Bay region have hauled up so many artifacts that a 2020 article in an archaeology journal organized the finds according to the means of discovery: those brought to light by shrimp trawlers, scallop dredgers, crab scrapers, or oyster tongs. There’s also activity in the Gulf of Mexico. Describing the work that she and others have done there, Jessica Cook Hale, a marine geoarchaeologist, told me, “You can’t fall off a boat in Apalachee Bay—on the east side of that bay—without bumping into a site.” Cook Hale is affiliated with the Submerged Landscapes Research Centre, at the University of Bradford, in England—an important global hub for specialists in the field.

Most discoveries are made accidentally. Recreational divers pick things up. Fishing boats snag objects in their nets. Amateur collectors near The Hague, in the Netherlands, regularly find tools, fossils, and bones on the shores of the Zandmotor, an artificial peninsula created with sand vacuumed up from the seabed. At Bouldnor Cliff, divers exploring the remains of a submerged ancient forest noticed that lobsters were flinging Stone Age tools out onto the seafloor as they dug their burrows.

Once sites are located, the painstaking task of exploration and excavation begins. Doing archaeology underwater poses special challenges. Limited by the amount of air in their tanks, divers have to work in short, purposeful bursts. They have to descend with special equipment: underwater writing slates, inflatable marker buoys and GPS units, pre-labeled plastic bags. There are animals to contend with: Eels defend their lairs; remoras harass you; jellyfish sting. Ocean conditions—cold water, strong currents, terrible visibility—can be tricky. Helen Farr, a maritime archaeologist at the University of Southampton, has described working in the North Sea as like “diving in cold tea.”

In November 2025, I flew to London to attend a conference at the stately British Academy titled “Taken at the Flood,” which brought together many of the leading figures in the study of underwater landscapes and archaeology. We were ourselves submerged, gathered in a windowless space on what the building map referred to as the “lower ground” floor.

The conference’s closing speaker was Geoff Bailey, a British archaeologist who has spent more than 50 years conducting research around the world, with a focus in recent decades on what lies underwater. His look is somehow both grizzled and dignified. In his final remarks, Bailey proposed a thought experiment: Imagine a distant future in which sea levels have risen about 200 feet—the sort of rise that might take place if Antarctica and Greenland were to lose all of their ice cover. To show us what Europe would look like with sea levels that high, he projected a map onto the wall. Britain and Ireland had been reduced to an archipelago of small islands. Northwestern Europe’s present coastlines and lowland areas lay deep underwater. Offshore, red dots lined the continent’s diminished periphery, indicating fully or partly drowned cities: London. Lisbon. Barcelona. Rome. Amsterdam. Copenhagen.

In this scenario, Bailey asked, what if archaeologists of the future could study only what remained above sea level, in places that today sit well inland from the coast? If they saw no evidence of sea-based culture in the cities that survived, what would they assume about life in 21st-century Europe? “They would think it was basically land-based,” he said, “with major centers of power in Madrid, Prague, Moscow—places like that. Because all of the capital cities of Western Europe would be underwater, and most of the infrastructure that supports our present civilization.”

That’s a bit of a stretch, but it does help bring into focus what’s been happening since the beginning of modern archaeology. In assembling a picture of our past, we’ve focused on what has survived on land (in the former highlands) while ignoring what lies underwater. The result is that we’ve assembled a picture of our past that is likely to be just as fragmentary and misleading as the one those future archaeologists might assemble of the world we live in today. We may have missed a lot.

What we won’t ever find, however, are the ruins of a lost civilization deep under the sea. That sort of thinking, wishful and pseudoscientific, is the province of the popular British writer Graham Hancock, whose book Underworld (2002) promoted the idea that advanced seafaring civilizations flourished during the last Ice Age and were then swallowed by rising seas, leaving only enigmatic traces behind. Its popularity drives specialists in the field crazy. “Cult stuff” is how the British marine geoarchaeologist Nicholas Flemming described it to me.

If the study of drowned ancient landscapes has a founding figure, it’s Flemming. Almost everybody I talked with for this article described him as a prime mover. So after the conference, I went to meet him at his home in Surrey, some 30 miles southwest of London. Flemming has had an astonishingly varied, adventurous, and productive career. It began in the 1950s, when he trained as a commando and diver with the Special Boat Service of the Royal Marines (roughly the equivalent of the Navy SEALs). He then pursued doctoral studies in oceanography at Cambridge. Over the past seven decades, Flemming has published more than 300 papers and reports and has also dived in the waters of more than 30 countries—continuing long after a car crash in the Balkans in 1969 left him paralyzed from the chest down. When diving from that point on, he used no special equipment: He swam with his arms rather than his legs and needed help only when entering and exiting the water.

Flemming, who is 90, has the look of a retired British adventurer from a bygone age. His hair is white, and he wears a walrus mustache that would have done Lord Kitchener proud. Seated in his wheelchair, he greeted me in his front hall and then, wasting no time on formalities, ushered me into his study. Flemming told me about the doctoral work he’d done at Cambridge, where he studied sea-level and tectonic change in the Mediterranean by surveying Greek and Roman harbors and ancient caves. As part of that effort, he worked on hundreds of submerged sites from classical antiquity. By the early 1960s, he had developed a conviction that much older sites might have survived underwater, and that he and others could find them.

Jamie Salmons for The AtlanticNicholas Flemming, 90, has explored the waters of more than 30 countries, continuing to dive even after an accident left him partly paralyzed.

Many archaeologists disagreed. Even when very old artifacts did occasionally turn up—most famously, perhaps, a 14,000-year-old deer-antler harpoon that a fishing vessel named the Colinda hauled out of the North Sea in a block of peat in 1931—they were treated as isolated curiosities. But Flemming interpreted them as confirmation that a whole drowned world of human history awaited discovery. “I knew what we were going to do and what we would find,” he told me. “And we did.”

A major milestone occurred in the summer of 1967, when, swimming in shallow waters off the southern coast of Greece, Flemming came across the ruins of a 5,000-year-old town, known today as Pavlopetri, where street grids, courtyards, and multiroom buildings had all survived. Archaeologists use a variety of techniques to date such sites: the reconstruction of ancient sea levels; the dating of the sediment layers in which the sites are found; comparisons of pottery, tool, and architectural styles to those that have been found on land; the radiocarbon dating of any surviving organic materials. Pavlopetri remains the oldest planned town ever found underwater.

In the decade that followed, Flemming continued searching for older sites. And in 1981, off a small island called Aghios Petros, he discovered the remnants of a nearly 8,000-year-old village. As he described it in his 2021 memoir, Apollonia on My Mind, the Neolithic villagers had picked an “ideal spot”—the underwater site, bordering a sheltered inlet and supplied with a freshwater spring, would once have stood on a peninsula that reached into the bay.

Others were making discoveries too. From 1978 to 1988, the Danish archaeologist Søren H. Andersen led intensive excavations in the Baltic Sea at the submerged settlement site of Tybrind Vig—excavations that yielded a wealth of preserved organic materials, many of them more than 7,000 years old, including canoes, decorated wooden paddles, fishing gear, bone tools, and plant remains. In 1984, while doing routine survey work in the Mediterranean, near Haifa, the Israeli marine archaeologist Ehud Galili discovered a site now known as Atlit-Yam: a 9,000-year-old submerged village of extraordinary completeness. It had houses, wells, and evidence of agriculture and ritual activity, including human burials.

By the early ’80s, Flemming was beginning to feel less drawn to the study of classical sites. He’d worked on hundreds, after all. “Okay, they’re very visual,” he told me. “They’re pretty. But one more Roman port?” Much older archaeology was what interested Flemming now—the “big game,” as he put it. “You could have Neanderthals living on the seafloor,” he remembered thinking. “You could have had elephants and rhinoceroses wandering on the floor of the North Sea and the Mediterranean.”

At the time, Geoff Bailey was starting to have similar thoughts. He’d begun his career in the 1970s by studying evidence of ancient coastal settlement. In particular, he studied accumulations of discarded shells, or shell middens, tens of thousands of which survive along the world’s coastlines, some of them hundreds of feet long and dozens of feet high. The layers of shells, piled up after their contents were eaten, preserve long records of human activity, including flaked stone, bone tools, the charcoal of old hearths, and sometimes evidence of human burials. Such sites began to appear in large numbers about 6,000 to 7,000 years ago, just as sea levels were gradually stabilizing—around where they are now.

In the ’70s, most archaeologists thought the explanation for this phenomenon was straightforward. While sea levels were rising, the theory went, coastal regions were simply changing too much to have supported the range of human activities associated with social complexity. But once sea levels settled, a sort of postglacial revolution ensued. “Boom!” Bailey said, describing that view to me. “Suddenly you’ve got this explosion of shell mounds, coastal settlements, fishing technology, dugout canoes, etc., all over the world.”

Bailey entertained doubts about that story early on. It seemed far more likely to him that people had been exploiting coastal environments, which are rich in resources and easy to move around in, for much longer than just the past 6,000 years or so. Wouldn’t it make more sense, he thought, if the “sudden” emergence of cultural complexity along the world’s coasts was simply a reflection of where and when the seas had stopped rising—and stopped covering up all the earlier coastal communities? Archaeologists, he felt, had fallen prey to evidentiary misdirection: The remains of communities on high ground had survived, whereas the original coastal communities had been washed away.

Owen Pomery

Others were pursuing related ideas. In 1975, the archaeologist Michael Moseley published The Maritime Foundations of Andean Civilization, in which he argued that much of the social complexity of ancient Peru arose along the coast, primarily powered not by agriculture, as was generally believed, but by the biological richness of the sea.

All of these ideas had important implications. If tens of thousands of years ago, people were living in significant numbers in coastal areas, they almost surely developed seafaring technologies and sophisticated navigational know-how long before we see any trace of such things in the terrestrial record. That would have enabled them to make longer and longer excursions at sea—to fish, to trade, or just to explore. To the underwater archaeologist George Bass, there was an obvious lesson in all of this, one that would help explain how people were able to spread so rapidly across the globe after migrating out of Africa. “Before there were either farmers or shepherds,” he wrote, “there were sailors.”

The study of submerged prehistory started with a relatively amateur focus on artifacts and has progressed to the scientific examination of sites. At the turn of the 21st century, a new phase began: the reconstruction of entire lost landscapes.

A major force behind this development was the English archaeologist Bryony Coles, who, while a professor at the University of Exeter in the 1990s, decided that she was tired of hearing people talk about the “land bridge” that had once connected Great Britain to continental Europe. By that point, enough artifacts had emerged from the North Sea, and enough was known about sea-level change during the glacial cycle, to suggest a very different picture. The North Sea basin had once been a fertile lowland, home to all sorts of plants and animals—and people. The whole area had been a place to be, it seemed to Coles, not just a place to cross.

During that time, Coles made a ferry journey from Britain to Sweden, which took her over a large, shallow feature of the seafloor known as the Dogger Bank. That crossing gave her an idea: To help dispel the land-bridge notion, why not borrow from the name Dogger Bank and call the whole submerged landscape Doggerland? And why not try to reconstruct what it used to look like?

Coles read everything she could find about seafloor terrain, sea-level change, artifacts and animal bones hauled up by fishing vessels, and the archaeology of adjacent coastal regions. In 1998, she published a paper—“Doggerland: A Speculative Survey”—that included a series of maps presenting Doggerland’s landscape during different stages of the glacial cycle. In Coles’s reconstruction, Doggerland had evolved from a near-empty polar desert at the height of glaciation (some 18,000 years ago) into a grassland of birch and willow grazed by mammoths, horses, and elk (as temperatures rose), then into a forested expanse of hazel and oak cut by big rivers and estuaries, and finally (by about 7,000 years ago) into a scattering of islands in the midst of the encroaching North Sea—the largest of which, now submerged, we know as the Dogger Bank. Coles’s paper sparked a conceptual revolution: Doggerland was a real place.

A few years after Coles published her article, Vince Gaffney, a British landscape archaeologist then at the University of Birmingham, and two colleagues, Ken Thomson and Simon Fitch, started to wonder: Might any of the companies that were prospecting for oil and gas deposits under the North Sea floor be willing to share the survey data they’d been gathering? It was a clever idea. By using the bounce-back of sound waves to identify features and anomalies deep below the seafloor—so-called seismic-reflection surveys—the companies had developed 3-D maps of the basin that were unparalleled in detail and scope. Gaffney and his colleagues suspected that those maps might include information about Doggerland.

One company, Petroleum Geo-Services, agreed to share some of its information, and once the archaeologists began analyzing the data, translated on-screen, they discerned the beds of an ancient river and its tributaries. “I just looked at it,” Gaffney told me, “and thought, Bloody hell, this is going to work.” He and his colleagues soon reconstructed a 25-mile stretch of the river, which they determined had been almost the size of the Rhine. In the decades since, Gaffney and his team—now based at the Submerged Landscapes Research Centre—have reconstructed more than 40,000 square miles of Doggerland. “If you put a line from Yorkshire to Denmark,” Gaffney said, “pretty much everything below that was at some point dry land, and we have largely mapped that area.” That makes Doggerland by far the most extensively studied “paleo-landscape” in the world.

“What this is,” Jonathan Benjamin told me, holding a large, greenish lump of rock in his hand, “is a beautiful hafted axe.” Benjamin was speaking via videochat from Australia, where he is a professor of maritime archaeology at Flinders University. He held the rock up to his computer so I could make a closer examination. To me, it looked more like a vaguely deformed mango than an axe, but Benjamin quickly helped me see it for what it was. He told me to imagine his forearm as a handle—the “haft”—and he then rotated the rock in his hand until I was looking at one of its narrow sides. All of a sudden, I saw an expertly tapered blade at the head of an axe—one that had lain underwater for millennia. Benjamin chopped at me from half a world away. “It’s still sharp,” he said.

That axe is just one of more than 260 Stone Age artifacts that Benjamin and his team discovered in 2019, in the shallow waters around Murujuga, part of the Dampier Archipelago, off Australia’s northwestern coast. This was the first site of such antiquity securely documented in tropical waters.

News of the discovery thrilled Nic Flemming, who had been arguing for decades that such sites would be found. In fact, back in 1982, with his infant daughter in tow, he had led a month-long survey of the Cootamundra Shoal, about 200 miles off Australia’s northern coast. The expedition, searching for ancient occupied terrain, was the first of its kind. Flemming didn’t expect to find any archaeological remains during this short outing, but he and his team were able to confirm that the conditions in the area were, as he put it in his memoir, “sufficient to support a Palaeolithic ice age human population during periods of low sea level.”

Benjamin and his team, aware of that work, had found their site by means of logical deduction. For years, they had conducted sophisticated survey work, using sonar, seafloor mapping, aerial imagery, and paleo-environmental modeling to identify promising areas for investigation. By 2019, they had narrowed down their target area so precisely that when they began diving, they quickly found what they were looking for: ancient stone tools and environmental evidence of a once-inhabited landscape. In 2025, they went prospecting again and found more stone tools, dating back at least 9,000 years. “We keep finding more sites,” Benjamin said. “Sites that make us ask even more questions.”

Benjamin’s team does its work in partnership with the Murujuga Aboriginal Corporation, which represents the traditional owners of the lands in that part of Australia. In recent years, it has become clear that the flood myths and stories that have been told for millennia by Indigenous peoples all over the world, often dismissed as primitive, fanciful, or at best symbolic, might encode historically accurate memories of past landscapes and areas of habitation in submerged regions of Aquaterra. Malik Churnside, an Aboriginal park ranger trained by Benjamin and his team so that he could take part in a recent dive, put this idea to me straightforwardly. Describing one of the tools that he’d found during a dive, he said, “It’s literally picking up pieces of history from these old stories from way back in the day.”

Nowhere is there a richer surviving body of such history than in Australia, where some traditional Aboriginal stories contain references to a now-drowned land known as Sea Country. Acknowledging this ancient oral history, Benjamin and his collaborators have named their research initiative “Deep History of Sea Country.”

Patrick Nunn, a geographer at the University of the Sunshine Coast, in Queensland, has devoted years to studying the ways in which some Aboriginal traditions preserve memories of coastal change. If a story refers to an identifiable landscape feature that’s now underwater, Nunn and his colleagues then use what they know about the history of the terrain and sea-level rise in that area to determine how long ago that feature must have been drowned—which in turn provides them with a minimum age for the story. To date, Nunn and his colleagues have identified 35 areas along the coast of Australia where Indigenous traditions preserve accurate memories of what Sea Country was like when it was land. The oldest stories, Nunn told me, concern the submergence of the Bass Strait “land bridge,” between the island of Tasmania and the Australian mainland, roughly 12,000 years ago. That’s a long way back. So far back, in fact, that, if Nunn is correct, these accounts may be the earliest surviving record of human experience, sitting right at what he calls “the edge of memory.”

Few of the sites that have been found in Aquaterra date back beyond 10,000 years. That’s starting to change as scanning and seabed-coring technologies improve, submersible drones become affordable, and industry data become more readily available. Geographers and archaeologists have now named Ice Age landmasses whose drowned lowlands dwarf even those of Doggerland. Between Siberia and Alaska, there’s Beringia, whose submerged portion is roughly the size of Greenland. Connecting Australia, New Guinea, and Tasmania, there’s Sahul, whose submerged portion is nearly twice the size of the Iberian Peninsula. And connecting mainland Southeast Asia with Sumatra, Java, and Borneo, there’s Sundaland, whose submerged portion is roughly a quarter the size of Australia. Those regions are now all understood to have been complex lowland ecosystems that for tens of thousands of years were home to all manner of flora and fauna. Their drowned portions are virtually unexplored—and all undoubtedly contain sites and fossils and landscapes that can help us answer big questions about human origins, global migration, and cultural development.

Cultural treasures might also await discovery. To imagine the possibilities, consider by analogy some of the great treasures found on land from our deep past: the lion-man of Hohlenstein-Stadel (roughly 40,000 years old), the astonishing art in Chauvet Cave (roughly 36,000 years old), the Venus of Willendorf (roughly 29,000 years old), the monumental Göbekli Tepe site (more than 10,000 years old). All were created at times when global sea levels were roughly 150 to 300 feet lower than they are today, in regions that lay considerably farther from the world’s coasts than they now do. If many people—probably most people—during those same eras lived in coastal regions, as people from every era always have, they will have left extraordinary things behind.

Aquaterra has not only a past but also a future. As sea levels rise, Geoff Bailey’s thought experiment is worth revisiting. If, over thousands of years, global warming were to melt our remaining ice sheets, the world’s oceans might rise another 200 feet. That would mean the drowning of another whole continent’s worth of land—and, once again, we’d lose coastal regions where much of human history and development has played out.

Bailey focused on Europe in his thought experiment, but with sea levels that much higher, many great cities all over the world would disappear. North America would lose New York, Miami, New Orleans, Houston, and Boston, among many others. In South America, Buenos Aires and Rio de Janeiro would go under; Africa would lose Lagos, Cairo, and much of Cape Town. Huge Asian population centers—Mumbai, Bangkok, Tokyo, Singapore, Jakarta, Shanghai—would drown, as would Darwin and Brisbane, in Australia.

[From the July/August 2024 issue: A wild plan to avert catastrophic sea-level rise]

The contours of the United States would be transformed. Florida would largely disappear. The Piedmont would become the country’s new east coast. Submerged monuments and memorials in Washington, D.C., might become popular dive spots. The Gulf of Mexico would fill in much of the Mississippi Valley. In California, an inland sea might spread into the Central Valley, drowning Sacramento and Stockton and almost reaching Fresno.

The point isn’t to lament that such things might happen. It’s to illustrate how skewed perceptions of our era would be if all of this terrain were removed from future consciousness. And that, in turn, is a reminder that exploring Aquaterra could help us answer some of the great open questions about our past.

When did people first leave Africa, and how did they make their way to Southeast Asia? How did people cross open water and reach Australia in numbers significant enough to settle there? No evidence survives of the boats and technologies that made those migrations possible, because many of the coastal regions where they were developed today lie deep underwater in Sundaland and Sahul. And what about the Americas? Did the first people to reach them live for millennia in the now-drowned landscapes of Beringia? Did they use watercraft to make their way along the now-drowned western coasts of North and South America? The objects and sites that can help answer such questions may well exist on, and only on, the world’s submerged continental shelves.

We live in an anomalous era. Aquaterra may be mostly water today, but for the greater part of human history—indeed, for the greater part of the past million years—it was mostly land. And that land is where we came from.

This article appears in the December 2026 print edition with the headline “The Lost World of Aquaterra.” When you buy a book using a link on this page, we receive a commission. Thank you for supporting The Atlantic.

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