Its shape is what first draws attention: not a circle, not a rectangle, but a D, with a straight north-west side running about five and a half metres and a curved wall completing the form. The whole thing measures only around four and a half metres across. It is easy to miss and easy to underestimate.

The enclosure is built in drystone, meaning no mortar holds it together, only the careful selection and stacking of stones. The wall is a single stone wide and tapers as it rises, reaching roughly a metre in height, with the lower courses made of large boulders that anchor the structure into the rough hill pasture. One particularly large boulder does double duty as the northern corner. What the enclosure was actually used for is not recorded. Sheltering livestock, penning animals during shearing, or serving some longer-forgotten agricultural purpose are all possibilities that this kind of small upland structure tends to prompt. The cliff face behind it may have provided a ready-made wall on one side, reducing the labour of construction. The interior is level, which on a mountain slope implies either deliberate ground preparation or a fortunate choice of location. Neither explanation makes it less curious.