The enclosure is subcircular, roughly forty metres across, and defined by an earth and stone bank with an external facing of drystone walling rising to about 1.2 metres. What gives it a quietly unsettling quality is the interior: the ground within sits up to a metre higher than the land outside, meaning that generations of burial have literally raised the floor of the dead above the level of the living. The single entrance, just a metre wide, opens to the west.

This kind of raised, bank-enclosed ecclesiastical enclosure is a recognisable feature of early medieval Ireland, where the circular or subcircular boundary, known as a cashel when built entirely of stone, demarcated sacred ground and sometimes the wider monastic precinct. The slight but definite elevation of the interior at Dunboyke is consistent with long and continuous use, the accumulation of successive burials gradually building up the soil within the protected area. A church stands at the centre of the enclosure, recorded separately as a companion site. The combination of a curvilinear enclosing bank and a centrally placed church is characteristic of early Christian foundation sites across the country, many of which were later absorbed into the medieval parish system and continued in use well into the post-medieval period.