The Neolithic people of Great Britain were prolific builders.
Just look at the British Isles—they are studded with countless ancient megaliths, hill forts, monumental graves, ritual sites and structures that archeologists have been collectively scratching their heads over for centuries.
In Ireland and to some extant, in Scotland, a wholly different kind of structure is found that are as inexplicable as the rest.
They are tiny artificial islands known as crannogs built by pounding wooden piles into the beds of lakes and waterways and topping them with dirt. In places where timber was unavailable, such as in the Outer Hebrides of Scotland, crannogs were built entirely of stones.
Why did Neolithic people invest so much time, effort and resources hauling stones, some up to 250 kilograms, to build islets at a place where there was no dearth of habitable lands or natural islands is a mystery.
A crannog at Loch Tay, near the Scottish Crannog Centre, Scotland. Photo credit: Ross Murray/Flickr
One theory goes that Ireland at that time was densely wooded, and apart from the upland areas, the lakes were practically the only place where one could see the sky. So the Neolithic people started building homes on artificial islands. Being surrounded by water also protected them from wild animals, so crannogs could also have served a defensive purpose.
Many crannogs show signs of habitation and over multiple periods of time, starting from the Neolithic, Bronze and Iron ages, right into Medieval times.
Eilean Dòmhnuill, on Loch Olabhat, on North Uist, Scotland, may be the earliest known crannog dating to 3200-2800 BC. Photo credit: F. Sturt
During the Iron ages, crannogs were probably the centres of prosperous farms, where people lived in an easily-defended location to protect themselves and their livestock from passing raiders.
The settlement would have consisted of a farm house, with cattle and crops being tended in nearby fields, and sheep on hill pastures.