The boundary is not a wall or a ditch in any dramatic sense, but a pair of low, grass-covered earthen banks with an intervening fosse, a shallow trench, running between them. A modern road cuts through it, a stream bisects it, a late nineteenth-century road has clipped its northern edge, and a house with a garden obscures another section. What holds the shape together, for anyone patient enough to read the landscape, is the accumulation of features inside: a church and graveyard, two holy wells, a structure traditionally identified as St Bericheart's House, several carved cross-slabs, and a bullaun stone, a boulder with one or more cup-shaped depressions used in early Christian ritual practice. Just outside the south-western bank, in what is still called Fair Field, sits another bullaun stone known as Clogh na h'Eilte.

The enclosure is the footprint of an early medieval monastic settlement founded by St Berihert, also recorded as Berichter. According to Harold Leask, writing in 1938, Berihert was traditionally the son of a Saxon prince who departed England following the Synod of Whitby in AD 664, the council at which the Roman and Celtic churches resolved their differences over the dating of Easter and the style of monastic tonsure. The Annals of the Four Masters, however, record the death of Berichter of Tulach-leis in AD 839, a date that has led some to suggest he may have been a grandson of that prince rather than the man himself. He was said to have had three sisters, among them Lassar and Ingen Buidhe, both of whom left traces in the local devotional landscape. Writing in 1858, the antiquary William Reeves noted that a structure called the comharbach, meaning the abode of the coarb, the hereditary successor to a monastic founder who held the community's lands and privileges, had once stood a few yards from the burial ground. By Reeves's time it was barely visible; the landowner had removed the stones.

Aerial photographs taken by Dr D.D.C. Pochin Mould revealed the banks as shadow features extending westward in line with the south wall of the graveyard, detail that is largely invisible at ground level. A visitor on foot will find the enclosure easier to sense than to see: the slight rise and fall of field margins, the broad flat-topped bank running west to north-west in the field north of the stream, and the faint square enclosure to the west of the graveyard, defined by a low bank, a shallow depression, and a scarp. The wells and the carved stones within the graveyard are the most legible survivals, and the cross-slabs in particular repay close attention.