Stonehenge may have long appeared to be the centrepiece of Britain’s prehistoric ritual landscape, but new research suggests it was only part of a far larger and more complex design. Archaeologists have now confirmed the existence of an enormous circuit of man-made pits hidden beneath the ground near Durrington Walls in Wiltshire — one of the largest prehistoric structures ever identified in Britain. Built between 3100 BC and 1600 BC, the complex reveals that the people who shaped this landscape were working to a vision far grander than previously imagined.
What exactly has been discovered?
The newly verified feature surrounds Durrington Walls and Woodhenge, within the broader Stonehenge World Heritage Site. Researchers have identified around 20 vast pits, each about 10 metres wide and more than 5 metres deep, arranged at regular intervals to form what has been named the Durrington pit circle. More than 4,000 years old, the pits were deliberately excavated, adding a vast engineered element to a landscape already famous for its above-ground monuments.
Professor Vince Gaffney of the University of Bradford told the BBC the pits were not only intentionally dug but positioned with striking precision relative to nearby monuments — a level of planning that required measurement, coordination, and a clear purpose.
When the pits were first identified in 2020 through large-scale geophysical surveys, some archaeologists hailed them as one of Britain’s largest prehistoric structures and even speculated whether their layout reflected early numerical counting. But sceptics argued they might simply be natural geological hollows.
A new study published in Internet Archaeology — pointedly titled “The Penis of Pits” — lays that debate to rest.
How did archaeologists prove the pits are man-made?
Because the pits are too large for full excavation, the team used a suite of scientific methods to investigate them non-invasively — an approach Gaffney called unprecedented for a site of this scale.
High-resolution scanning revealed a circular pattern of deep voids beneath the soil. Electrical resistance tomography was then used to estimate each pit’s depth, while radar and magnetometry showed their steep, deliberate shapes.
To determine their origin, researchers extracted narrow sediment cores and analysed them using:
- Optically Stimulated Luminescence (OSL) to date when the soil was last exposed to sunlight
- Sedimentary ancient DNA (sedaDNA) to identify traces of animals and human activity
The cores revealed evidence of sheep, cattle and long-term human presence — clear signs of an inhabited, managed landscape rather than a natural geological formation. OSL dating confirmed the pits were dug in the late Neolithic and remained open or maintained for nearly 1,000 years.
The repeated sediment signature across multiple pits clinched the case.
“They can’t be occurring naturally,” Gaffney told The Guardian. “It just can’t happen. We think we’ve nailed it.”
What might the pit circle have meant?
While archaeologists caution that the exact purpose remains unknown — the builders left no written records — the scale alone rules out casual or functional ditch-digging. Excavating nearly 20 enormous shafts into solid chalk, spaced across more than a mile, required planning, labour and a shared cultural vision.
One emerging theory suggests the circle was tied to ideas of an underworld, in contrast with Stonehenge’s solar alignments. Gaffney says the new discovery shows Neolithic communities inscribed their cosmology onto the land on a monumental scale:
“Now that we’re confident the pits form a structure, we’re looking at a massive monument inscribing the beliefs of the people onto the landscape in a way we’ve never seen before.”
The pits appear to have remained significant for centuries, with later communities continuing to acknowledge or maintain them even as cultural practices evolved.
A transformed view of the Stonehenge landscape
The new research fundamentally reshapes how archaeologists understand Stonehenge. Instead of viewing the famous stone circle in isolation, scholars now speak of a coordinated ritual landscape, engineered both above and below ground.
What was once speculation is now confirmed: the Durrington pit circle was a deliberate, monumental human creation — a hidden dimension of prehistoric architecture that adds extraordinary depth to the story of Stonehenge.
