Poulnabrone neolithic tomb

Went for a spin on the bike today and passed this megalithic monument. Poulnabrone (Poll na Brón in Irish, from "Poll" -- hole, and "Bró" --- quern, so "The hole in the quernstone") is a Neolithic Dolmen, or portal tomb, in the Burren, Co. Clare . It's the largest example of such a tomb in Ireland. The remains of at least 33 people were found here and carbon dating indicates that it was used as burial site between 3,800BC and 3,200BC.