This national monument is in a chain of five megalithic buildings along this ancient route in county Sligo. It dates from the Neolithic period (c.2500-4000 BC) and consists of a wedge-shaped cairn and an oval-shaped court. The court area measures 45-feet by 27-feet and is among the largest in the country. This leads to the burial gallery which is divided by upright stones into two chambers followed by another three which were originally covered by a corbelled roof. Excavations in 1935 uncovered four cremation burials, Neolithic pottery, polished stone axes, flint knives and scrapers, and two clay balls. The court was reused in early Christian times by iron smelters, and the remains of a kiln from this time can be seen.