According to William C.Borlase, one of the greatest authorities on the dolmens of Ireland, the covering stone of the Brownshill Dolmen is not only the largest in Ireland, but the largest in Europe. Writing about the site in 1897, William Borlase describes two other dolmens on the hill, one of which was just 45m distance from this Dolmen. The massive granite capstone rests on two portal stones which flank a doorstone and slopes downwards to the West where it rests on a low boulder. The chamber structure is open to the North and there is no trace of a surrounding cairn or mould which sometimes exists. How in those primative times such an enormous mass of stone was raised still remains a mystery.
The name "Dolmen" comes from two Breton words meaning "Stone Table". The word "Cromlech" is a modern Irish term composed of two Celtic words (crom stooping, and leac, a flagstone), meaning the stooping stone . Two hundred years ago, it would have been called a Druid's alter.