Artificial islands ain’t what they used to be. These days, they’re often billionaire playgrounds in Dubai or airports that look like Bond villain headquarters. But humans have been building fake islands for thousands of years, and some of the oldest examples have been resting under Scottish lochs since the Neolithic era. What they were used for, researchers don’t know yet, but we recently learned more about them than we ever have before.

A recently published paper in Advances in Archaeological Practice focused on these so-called “crannogs,” which are small human-made islands built from wood, stone, and brushwood. They can be found all across Scotland. Archaeologists studying a crannog at Loch Bhorgastail on the Isle of Lewis discovered the site is more than 5,000 years old, putting it in the same age range as Stonehenge, killing the assumption that most crannogs were more of an Iron Age thing.

The island itself started as a circular wooden platform roughly 75 feet across. People kept adding to it over the centuries, layering brushwood and stone on top as a kind of multi-generational communal construction project. Researchers also found a sunken stone causeway connecting the island to the shore. This means, at one point, it wasn’t as isolated as it is today, and it was more easily accessible.

It wasn’t just a random pile of rocks, as hundreds of fragments of Neolithic pottery archaeologists uncovered, some of them carrying traces of food residue, suggest this was a hotspot for communal gatherings, cooking, and big feasts. It seems to have been more of an elaborate Neolithic dining venue, like a popular restaurant.

It’s Not Just the Artificial Islands, It’s the Tools Used to Find Them

Probably the biggest breakthrough, other than the uncovering of the crannogs themselves, is the method the researchers used to dig them up. One of the biggest enemies of archaeology is something you wouldn’t guess would be such a big problem: shallow water. You can’t use the same methods as a traditional land survey, and deepwater marine tools don’t function well in water that’s only about a meter deep. They even have a name for this annoying zone: a “white ribbon.”

White Ribbons are areas that, when viewed from high above, appear as a white ribbon of shallow water between the shore and deeper waters. These areas are often loaded with potential archaeological discoveries, but they don’t make specialized tools for exploring this very specific strip.

So, the team developed a stereophotogrammetry system using waterproof stereo cameras operated by divers alongside drone imaging above the surface. This allowed them to create a seamless 3D model of both land and underwater structures with incredible accuracy.

Now, with this tool in hand, born from a mix of desperation and creativity, this team and many others like them have a new toy that can finally lay the shallowest parts of Scotland’s lochs bare like they never have before.