A souterrain, which is a stone-lined underground passage or chamber typically associated with early medieval settlement and used for storage or refuge, once ran beneath the ground here. By the time anyone thought to record it properly, its fabric had already been dismantled, deliberately and not so long ago.

When a researcher named Broker documented the site in 1937, he was already writing in the past tense about the structure's physical remains. He recorded a passage leading to a stone-built underground chamber measuring seven feet long, three feet wide, and four feet high, along with three flagstones lying on the ground surface and two further stones marking the entrance to the chamber. But all of these stones had been removed by the landowner in 1924, more than a decade before Broker's visit. He was, in effect, recording a memory of a structure rather than the structure itself. What he could still identify were two hollows in the north-western quadrant of the ringfort, the subtle depressions left where the chamber and passage had been, the ground still holding the faint shape of what it once enclosed.

The ringfort itself survives, and the two hollows in its north-western quadrant remain the only visible trace of the souterrain beneath. There is nothing dramatic to observe, but the slight dip in the ground carries a quiet archaeological logic: once you know what caused it, the landscape reads differently.