The capstone of the Tirnony Dolmen is supported by three of six upright stones, two of which form the portal. It is believed to be a 5,000 to 6000-year-old megalithic burial tomb.
The dolmen is remarkable for the free-standing orthostat, 1.8m high, which is beside one of the portal-stones. Behind the tilted capstone is a well-defined square chamber.
