What makes it stranger still is that the hillfort was partly built from the cairn's own stones. The people who constructed the later enclosure did not simply build around the ancient mound; they quarried it, dismantling a monument that was already perhaps a thousand years old to get at the raw material beneath.

The cairn dates to the Early Bronze Age, identified through finds including two small bone pins, several vases, and a perforated bone plaque. Roughly circular and about 23 metres in diameter, it was bounded by a kerb of medium-sized vertically set stones, with a second, inner kerb of somewhat smaller stones concentric to the first, set about three metres inside it. When archaeologist Gerhard Bersu excavated the site in 1951, and when Joseph Raftery published those findings in 1969, they found the remains of at least eighteen individuals within the mound. Most had been cremated, though three were inhumations, meaning the bodies had been buried intact rather than burnt. The burials were concentrated in the eastern half of the mound, with one lying just outside it entirely, about one and a half metres to the east. They were placed in pits and in cists, the latter being small stone-lined boxes or chambers used to contain the dead.

By the Iron Age, the cairn had been substantially altered. A circular wall roughly 18 metres across and a larger oval enclosure measuring 37 by 30 metres were built across and around it, with the cairn itself robbed for stone to build these later structures. One of the original cists was cleared of its burial remains and put to an entirely different use, repurposed as a hearth. It is a quietly unsettling detail: a chamber built to hold the dead, emptied out and used for fire.