Three large roofing slabs now lean against the gallery walls rather than sitting above them, and a lintel has slipped westward from where it once capped the entrance. The overall effect is of a monument in the process of slow dissolution, though the underlying logic of its design remains clear enough to follow.

Court tombs are among the oldest megalithic monuments in Ireland, generally dated to the Neolithic period, roughly 4000 to 2500 BC, and are distinguished by their segmented stone galleries and formal entrance arrangements. This particular example follows the type closely. A gallery running east to west, approximately five metres long and just under one and a half metres wide, is divided into two chambers by upright jamb stones set into the sides. At the eastern end, two portal stones mark the original entrance. The measurements and layout recorded by Ruaidhrí de Valera and Seán Ó Nualláin in their 1972 survey of the megalithic tombs of Ireland place it firmly within the regional tradition, one of several such structures documented across County Galway and the wider western seaboard. The name Tonadooravaun is that of the townland, and the tomb occupies the kind of marginal upland ground that Neolithic communities across Ireland often chose for their monuments, elevated and oriented with some deliberateness toward the wider landscape.