In 2020, archaeologists in the United Kingdom made a surprising discovery. At Durrington Walls, a large Neolithic henge not far from Stonehenge, they found more than a dozen large, deep pits buried under layers of loose clay.
The pits are mysterious. Each one measures roughly 30 feet wide by 15 feet deep, and together they form a mile-wide circle around Durrington Walls and neighboring Woodhenge. They also appear to be linked with the much older Larkhill causewayed enclosure, built more than 1,000 years before Durrington Walls.
For the last few years, archaeologists have been puzzling over their origins: Were they dug intentionally by human hands? Were they naturally occurring structures, like sinkholes? Or is there some other possible explanation for the existence of these colossal shafts?