The walls are low, barely ten centimetres above the ground in places, and thin, around half a metre across, but they trace a roughly rectangular area of approximately 180 metres by 90 metres. What makes them quietly arresting is not their scale but what they imply: that this wet, rough ground was once organised, divided, and worked.

These are relict field boundaries, the remnant skeleton of a former agricultural landscape that the bog has slowly swallowed. They extend to the south-west from two nearby prehistoric monuments: a radial-stone enclosure and a four-poster, which is a small setting of four standing stones, a monument type generally associated with the Bronze Age. The proximity of these boundaries to such structures suggests the landscape here was being managed and subdivided during prehistory, though the bog has made precise dating difficult. The area has been partially reclaimed in more recent times, levelled and surface-seeded, which means the surviving traces represent only what the intervention left behind. Occasional loose stones scattered across the bog surface are thought to have fallen from the walls as the ground shifted beneath them over the centuries.