It is easy to walk past without registering its geometry, but look closely and the incised design rewards attention: a cross set inside a rectangular frame, with a diamond at its centre, triangular terminals at each arm, and two short additional crossbars, one plain and one finished with small circular ends.

The slab is slightly tapering in form, and the decoration is worked in single incised lines rather than relief carving, a technique common in early medieval Irish stone sculpture. The cross-in-frame type belongs to a tradition of commemorative or boundary markers associated with monastic enclosures, where carved slabs served to mark graves or sacred ground. Glendalough, which developed into one of the most significant monastic centres in early medieval Ireland, accumulated a large body of such carved stonework over its long centuries of use. The Priest's House itself, a small Romanesque structure within the main graveyard, was described and recorded by Robert Cochrane in his detailed survey of the ecclesiastical remains at Glendalough, published as part of the Eightieth Annual Report of the Commissioners of Public Works in Ireland for 1911 to 1912. A drawing of the slab appeared in that report. The architectural historian Harold Leask returned to it in 1950, providing the precise description of its design that remains the standard reference for the stone.