Some 4,500 years ago, people dug a series of deep, wide pits in the area near Durrington Walls in southern England. They were gemometrically arranged, forming a 2-kilometer (1.2-mile) wide circle that enclosed over three square kilometers (1.16 square miles).

Long mistaken for naturally occuring features, the circle of human-made shafts has now come to be understood as a colossal project that lends new dimensions to the Stonehenge landscape.

An invisible ring around Durrington Walls

Durrington Walls is just a stone’s throw from the small English town of Amesbury, and just three kilometers, or about half an hour on foot, from Stonehenge. Each pit or shaft is approximately 10 meters (32.8 feet) wide and 5 meters deep.

Of the 20 pits discovered so far, a new study suggests that at least 15 form a huge, even circle around the henge of Durrington Walls. A henge is a type of prehistoric earthwork consisting of a ring-shaped bank, fortified with an inward ditch, encircling a flat circular area.

They were likely used for ceremonial purposes, to congregate or perform rituals. At the center of Durrington Walls used to be a circular structure of wooden posts, driven deep into the ground and surrounded by a settlement.

The pit structure forms a ring around Durrington WallsImage: Environment Agency 2024

The pits were discovered years ago, but the newest research is just now uncovering more details, and providing deeper understanding. Scientists have now been able to date the structure to about 2480 BCE using optically stimulated luminescence (OSL).

The OSL method is a fairly precise way of pinpointing a sediment’s last exposure to light — and by extension, the last time it was covered or buried — by measuring the natural radiation captured in certain minerals like quartz and feldspar. This technique relies heavily on the quality of the sample and has a margin of error of about 5-10%.

The recent study shows that the circular structure did not accidentally form over centuries, but was the result of intentional efforts in a planned, momunental project. The pits were actively used as part of the cultural landscape — and traces of humans, plants and animals indicate deliberate coordination.

A ‘sacred boundary’ mapped with astounding precision

None of the shafts examined can be attributed to natural erosion of the chalky landscape — the pits’ sheer size and number clearly suggest they were dug by humans. They form a near-perfect circle, and are spaced at even intervals. The width and distance of the pits follow a clear pattern.

This means that the humans involved were able to mark distances, count steps or measurements, and work out a coordinated plan — all before they started digging. And so, what at first glance seemed like an assortment of strange holes became a rare testament to the fact that numbers, measurements, and large-scale planning were already part of the daily lives of Neolithic people living in the area.

A portal to the underworld?

The authors of the recent study believe this mathematical design directly related to people’s beliefs about the world at the time. The researchers suggest that each pit marks not only a point in the circle, but also a symbolically lowered space — a kind of underworld — to deposit animals, sacrificial offerings and cult objects.

Archeologists interpret the ring of shafts as a kind of "sacred boundary" marking the area around Stonehenge and Durrington Walls. It could have been used to guide peoples’ movements — or even entire processions.

Visitors looking out over the flat plain today cannot make out this boundary.

Neolithic monuments across Europe

Neither Durrington Walls nor Stonehenge are isolated structures. They belong to a network of Neolithic monuments spanning the British Isles, from the stone circles and circular ditches of Salisbury Plains to other henge formations with pits and ditches as far as Ireland and Scotland — and further still.

Similar discoveries show that around 2700 BCE and 2200 BCE, prehistoric groups from southern Britain, northern Europe, central Germany and the Iberian peninsula were in active exchange.

What’s known as the bell-beaker culture, with its eponymous bell-shaped ceramic vessels, even established a transregional network of trade and exchange, as the archeologist Franziska Knoll of the State Office for Heritage Management and Archeology Saxony-Anhalt told DW.

Knoll has been investigating the circular sanctuary of Pömmelte just south of Madgeburg in central Germany. Here, too, are circular structures that echo those of Durrington Walls — although, at just 2 meters deep, they do not match the scale — with cattle bones, ceramics, stone axes and other objects intentionally deposited within.

The pits in Durrington Walls will not be excavated in the near future for financial reasons. But Knoll hopes to soon find out what exactly was deposited in the British shafts. Although she was not involved in the present study, she says she’s like to learn more about when exactly the pits were dug.

This article was translated from German.