The Brownshill Dolmen is a megalithic portal tomb situated 3 kms east of Carlow town.The capstone at Brownshill, weighing an estimated 100 metric tons, is reputed to be the heaviest in Europe.
Officially known as the Kernanstown Cromlech, it is also spelled as Browneshill Dolmen. It is sited on a hill on which sits the former estate house of the Browne family from which the hill takes its name.
It was built between 4000 and 3000 BC by some of the earliest farmers to inhabit the island. The capstone is thought to have been covered by an earthen mound and a gate stone blocked the entrance. At Brownshill both portal stones and the gate-stone are still in situ; the capstone lies on top of the portals and gate-stone and slopes to the ground away from the entrance. Not much additional information is available on Brownshill because it has never been excavated.