Lierne vaulting is a late medieval decorative technique in which short ribs connect the main structural ribs of a ceiling or vault, creating an intricate geometric pattern. The edges of this stone are bordered with cable work in relief, there is a boss on its top, and a mortice cut into its back suggests it was once fitted into a larger structure. What that structure was, nobody has been able to determine.

The stone is one of three fragments from a chamfered limestone arch, a style of arch where the edges are cut away at an angle, with a combined span of 1.5 metres. Writing in 1854 to 1855, a commentator named Hitchcock described a building nearly opposite Dingle's Market House, known as Hussey's Castle, as having an arched passage and very thick walls. By the time the site was examined more systematically, only the arch stones and the decorated slab remained. A third stone was recorded as still present in 1918, but has since been lost. The site of the original building is now occupied by what was Moran's Drapery, and the decorated stone rests in the garden to its rear. The masonry points clearly to medieval origins, and the quality of the carving suggests this was no ordinary doorway, but the building it belonged to has left almost no other trace above ground in Dingle's busy streetscape.