This kind of monument, sometimes called a gallery tomb or court tomb, is a long chambered structure built from large upright stones during the Neolithic period, typically used for communal burial. What makes this particular example worth attention is not grandeur but detail: the overall gallery runs to ten metres in length, oriented northeast to southwest, and enough of its original architecture remains in position to read the logic of its construction.

A septal stone, a dividing slab set across the interior to partition the space, separates a short entrance portico of roughly 1.4 metres from the main gallery chamber behind it, which extends a further 7.2 metres. Six sidestones survive along the north wall, five along the south, and a backstone closes the eastern end. There is also a single upright stone on the north side that appears to double the gallery wall, and a line of five stones running along the south exterior that may be the remnant of an outer enclosing wall. The whole structure is set within an irregularly shaped mound, across which a number of displaced slabs now lie scattered. The site sits roughly 210 metres south of a separate portal tomb in the same area, making this a landscape that was clearly significant to Neolithic communities over an extended period. The monument was described by O'Flanagan in 1927 and later surveyed in detail by Ruaidhrí de Valera and Seán Ó Nualláin in their 1972 volume on the megalithic tombs of Connacht and the midlands.