It is a cross base, the kind of socketed plinth into which a free-standing stone cross would once have been fitted, and it survives in a notably complete and legible condition, even if the cross it once held is long gone.

The stone measures roughly 0.78 metres by 0.58 metres and stands only 0.12 metres high, so it reads less as a monument than as a heavy, purposeful piece of masonry. What makes it worth examining closely is the precision of its construction. A rectangular mortise, meaning a slot cut to receive a tenon or upright, passes entirely through the stone and measures 0.3 metres by 0.12 metres. A groove has been cut parallel to the front face of the base, returning at a right angle for a short distance along one end, suggesting the cross it supported was shaped and seated with some care. The material itself, mica schist, is a metamorphic rock with a faintly glittering, layered quality, and it was available locally in the Wicklow uplands. The base was recorded by Patrick Healy in his 1972 unpublished survey of ancient monuments at Glendalough, compiled for the Office of Public Works, at which point it was located south-east of the Priest's House, one of the small Romanesque structures within the monastic enclosure. By 2005 it had been moved into storage at the visitor centre, presumably for protection.