What makes it peculiar is its shape. Rather than the familiar Latin cross, it forms a T, the crossbar sitting flush at the top with no upright above it. This tau form is rare in Irish stonework, and this example carries an additional strangeness: on each arm, a carved head faces inward toward the centre, hooded, long-necked, and identical to its twin. Between the two heads run three raised transverse ribs. The cross known on the Ordnance Survey six-inch maps as Cross Inneenboy, meaning the cross of the daughter of Baoth, is a piece of early medieval carving that has spent much of its existence being argued over, moved, and moved again.

Originally it stood on Roughan Hill, close to the road between Kilnaboy and Kilfenora in County Clare, set into a large outcropping boulder and aligned northeast to southwest, adjacent to a cashel (a stone-walled early medieval enclosure) and a souterrain (an underground stone-built passage associated with early settlements). It was removed from this location on several occasions and returned, and when the antiquarian T. J. Westropp photographed it in 1894 it had only recently come back after an absence of some thirty years. Scholarly disagreement has followed it throughout. In 1937, Dr. Adolf Mahr proposed that its T-shape placed it within a La Tène tradition, the decorative style associated with Iron Age Celtic cultures across Europe. By 1967, Etienne Rynne had countered that its stylistic affinities with nearby Romanesque monuments pointed instead to a medieval boundary or termon cross, marking the ecclesiastical territory of Kilnaboy. Peter Harbison, writing in 2000, offered another reading: that the cross may have been modelled on a T-shaped crozier reliquary, a type of staff-shaped relic container, and that it may have stood along a pilgrimage route through north Clare. T-shaped croziers do appear carved on monuments in the immediate area, including the Doorty Cross at Kilfenora and the high cross at Dysert O'Dea. As for the carved heads and their three ribs, Máire MacMahon proposed in 2017 that the ribs represent a wound of decapitation, interpreting the imagery as a Christianised adaptation of the older Celtic motif of the severed head, transformed into a symbol of martyrdom. The cross's shaft also raises a practical puzzle: a fragment of stone now held at the OPW Depot in Athenry was photographed beside the cross in 1894 and may belong to its base, but it does not fit the existing shaft directly. If a missing middle section once connected them, the cross would originally have stood well over 1.5 metres high.

The original stone is now displayed at the Clare Heritage Museum in Corofin, where it can be examined closely. A replica stands in its place on Roughan Hill, giving some sense of how the cross would have appeared in its landscape setting beside the cashel and souterrain, though the split between original and copy is part of the cross's own unsettled history.