Poulnabrone dolmen (Irish: Poll na Brón) is a large portal tomb located in the Burren, County Clare, Ireland. (Irish: Boireann, Contae an Chláir, Éire). It has three standing portal stones supporting a heavy horizontal capstone. The structure is about 1.8 meters in height and stands in the centre of a cairn on a limestone pavement. It is thought to date to between 4200 BC and 2900 BC. Dolmens are a type of single-chamber tomb or burial chamber. They could be covered with earth or smaller stones to form a tumulus or mound. What can often be seen now is the intact stone structure that would have been under the mound, the covering having weathered away over the centuries. There are approximately 172 dolmens in Ireland. Poulnabrone dolmen is located about 5 miles (8 km) south of Ballyvaughan. It is in a rocky field in the remote and high altitude townland of Poulnabrone, Kilcorney (Irish: Cill Choirne), close to the R480 road.