In 1931, a fisherman named Pilgrim Lockwood was  sailing 40 km off the eastern coast of England when he noticed a strange object in the nets that  his crew had been dragging across the sea floor.

It was a harpoon carved from the  antler of a deer, measuring over  20 cm long with a sharp, barbed edge.

Lockwood’s discovery confirmed that this area of the North Sea, which for years had been hypothesized to be a lost submerged land, was once  a place that ancient people had called home.

And other discoveries since then have revealed  that those people weren't just Homo sapiens… At various points in deep time, Neanderthals,  and maybe even older human relatives, roamed this long-lost world.

And for a pretty good reason, too.

This  area - which connected Britain to the   rest of Europe - was once one of the  continent's richest hunting grounds… A dynamic and, at times, lush  environment that supported a   wealth of species and natural resources.

To ancient humans, it was something  of an ecological paradise.

So what happened to this piece of prime  prehistoric real estate?

How did it   end up beneath the waves, leading to a great  British break off from the European mainland?

While a massive megatsunami might have drowned  it for good, the underlying reason that it now   lies under the sea may have actually been the same  thing that made it so great in the first place.

Tales of mysterious, sunken worlds are a  popular trope in stories about our past, but in most cases, they’re myths  with problematic histories,   and they have no actual archeological basis.

But in the area that’s now the North Sea,   between Britain and the rest of Europe,  one sunken world really did exist!

Scientists call it Doggerland, after  a type of Dutch fishing boat called a dogger that sailed across parts  of the area in the 17th century.

I myself would prefer "Doggoland" and it's  just like a land full of puppies, and you   take a vacation there and just boop the snoots.

The first clues suggesting that this region was a   former landmass came in the early 20th century.

Locals had long noticed that when tides were   especially low, some coastal areas  of the North Sea revealed evidence of   sunken forests that were clearly extremely old.

But it took Lockwood’s discovery of that antler harpoon to prove that Doggerland wasn't just a  submerged piece of land, but also a place that   had once been occupied by ancient people.

And this has been confirmed over and over   again in the years since, thanks to a variety  of tools, pottery fragments, and even human remains that have been dredged up from the  sea floor or found washed up on the coasts.

The oldest of these remains is a skull  fragment of a young male Neanderthal,   referred to by researchers as Krijn, which dates  to somewhere between 50,000 and 70,000 years ago.

And we’ve even found Neanderthal-type  artifacts left behind by Krijn’s people, including a sophisticated flint tool bound  together using tar from a birch tree.

Back when Neanderthals roamed this  area, in the depths of the ice ages,   Doggerland was mostly frigid tundra.

It  was part of what's called the ‘mammoth   steppe’ that stretched the  length of the continent.

And in fact, as far as we can tell, Doggerland  seems to be right at the northernmost edge of   the Neanderthals’ range during their  heyday, in the Pleistocene Epoch.

They lived alongside many cold-adapted species  characteristic of this time period.

We’ve   found the remains of mammoths, woolly rhinos,  cave lions, and hyenas, just to name a few.

But sediment cores collected from the  seafloor have shown that, as the ice ages came to an end around 10,000 to 15,000  years ago, Doggerland changed dramatically.

The cores contain deposits of peat – organic  material that can only form in swampy marshland.

This revealed that, as the northern  glaciers retreated and the region warmed, the tundra was replaced by woodlands,  swamps, mudflats, and plentiful fresh water in the form of lakes and river systems.

And while the Neanderthals were long gone by this   time, by about 13,000 years ago, a wave of Homo  sapiens hunter-gatherers migrated into the area.

They were probably following herds of elk,  deer, wild boar, aurochs, and bison into   the emerging greener and wetter landscape.

Doggerland is now considered to have been one   of the most resource-rich and human-friendly spots  on the entire European continent during this time,   thanks to its concentration of  prey and freshwater resources.

But understanding the complex  lives and cultures of the people   who lived in Doggerland is a real challenge.

It’s a difficult task at any archaeological site,   let alone one that is now  almost entirely submerged.

Still, researchers, beach-combers, and lucky  people fishing have found over 1000 artifacts so   far that date to this period of human occupation,  known as the Mesolithic or Middle Stone Age.

Many of them are hunting weapons, often carved  from the bones of prey animals - primarily deer,   like Lockwood’s harpoon.

But some have even been   fashioned from the bones of other humans.

And isotopic data has been gathered from the   remains of these Mesolithic people, which helps  us figure out what kinds of food they were eating.

See, different foods contain different chemical  markers, and seeing as you are literally what you eat, those markers persist in the remains of  people even thousands of years after their death.

And the data suggests that they  had a mixed surf n’ turf diet,   including mostly freshwater fish  and some terrestrial animals.

Mmm!

Good eatin'...

While there’s a lot that we’ll  never know about how they lived,   they were clearly adept at making the most of  the resources that Doggerland had to offer.

But - spoiler alert - it would not last.

By about 8000 years ago, Doggerland was   gone.

An entire land mass with an area comparable  in size to Britain was lost beneath the waves.

But how, and why?

Well, what had made this low-lying area so   idyllic was its abundance of water in the form of  rivers and lakes that supported a lush ecosystem.

But, as temperatures continued to  rise and ice-sheets continued to melt,   water became too abundant.

And this happened gradually   at first, then all at once.

See, it wasn't just a simple   case of rising sea levels and widening river  systems that eventually swallowed Doggerland   whole - that was only part of the story.

Because in the 1980s, scientists discovered   evidence of a massive megatsunami that  hit the North Sea about 8000 years ago.

This huge wave was generated by an undersea  landslide off the coast of Norway called the   Storegga Event that dumped an enormous amount  of debris into the ocean, causing a huge wave   to ripple across the North Sea.

But did this catastrophe drown   Doggerland and its people in a sudden,  practically overnight apocalypse?

Well, to answer that question,  it’s critical to know how much   of the landmass was still above  sea level when the tsunami hit.

And that has been a subject of much  debate over the last few decades.

I mean I can't go to a cocktail  party where people aren't talking   about Doggerland's sea level orientation.

Those are the friends I hang out with, though...

But recent studies have suggested that Doggerland   had already changed quite a bit in  the time leading up to the tsunami.

Being an especially low-lying area,  rising sea levels triggered by glacial   melt had already inundated much of the region.

By the time the tsunami hit, it’s now thought   that only a few parts of Doggerland were left.

One of them was an island called Dogger Island,   which would have still been high and dry  at the time of the Storegga landslide,   and part of it may have survived the  event for a few centuries afterwards, too.

So, as powerful as the tsunami no doubt  was, it was probably an additional,   dramatic hit to a place already doomed  by larger-scale, gradual planetary  changes that eventually sealed its fate.

Now, while all this scientific exploration of Doggerland makes it the best known sunken  landmass occupied by humans, it isn’t the only   prehistoric real estate we’ve lost to the ocean.

During the ice ages, there were many areas   of the continental shelves that  were exposed around the world.

Some of those areas would have been  important sites for humans.

Take, for example, Atlit Yam off the coast of Israel, or  even areas off the coast of Southern California,   which have been the subject of underwater  surveying over the last couple of years.

And regardless of the way Doggerland  finally sank under the waves, it shows   us that some undersea worlds really do exist.

It reminds us that the history of life on this   planet has always been shaped by constant  environmental change – change that can even   create and destroy the places we call home.

While human civilization has changed a lot   since Doggerland’s demise, we are entering a new  period of sea-level rise - this time caused by us.

And Doggerland’s story is a  reminder that we are still   vulnerable to the same forces  as our Mesolithic counterparts.

In a few thousand years, who knows  which now-familiar locations will