It is too regular to be entirely natural, too worn and unrecorded to be easily explained. Oval in plan, roughly fifty metres along its longer axis, with steeply sloping sides and a broad, flat summit, it may have begun as a natural glacial or geological feature that was then shaped and modified by human hands at some point in the past. That uncertainty, sitting between landform and monument, is precisely what makes it interesting.

The earthwork is layered in ways that repay careful attention. A fosse, a ditch cut to define and defend the base of a structure, runs around the mound's perimeter, though much of it has been swallowed by the surrounding marsh and survives only as a faint depression. At the south-west, a low stony rise, just thirty centimetres high, may be the last remnant of an outer bank that once completed a more substantial enclosure. On the summit, a raised oval platform, some twenty-one metres by twelve, sits slightly apart from the mound's edge, separated by a narrow gap and, along part of the circuit, by the remains of a low bank. A gently sloping terrace breaks the steepness of the sides to the south and south-west, suggesting deliberate landscaping rather than simple erosion. More telling still is the northern slope, where a semicircular quarry pit has bitten into the mound and appears to have partially destroyed what may once have been a causewayed entrance ramp, a raised approach leading up to the enclosure's interior. A second enclosure of the same general type lies roughly fifty metres to the west, which raises the possibility that these two features formed part of the same complex or were at least related in function and date, though what that function was remains open.