Poulnabrone is a portal tomb on one of the highest and bleakest stretches of the Burren, south of Ballyvaughan: three standing stones holding up a great tilted capstone, silhouetted against the sky above the limestone pavement. It dates from the early Neolithic, roughly 3800 to 3200 BC. It isn't the biggest of Ireland's 172 or so dolmens, but it's the best known and the most photographed.
What you see is only the stone skeleton. The tomb would originally have been covered by a mound of earth and stones. Excavations in 1986 and 1988 found the remains of around 33 people, adults and children, buried here over some 600 years, along with stone and bone objects placed with the dead. It's a short walk from the road and busy in summer; come early or late for the best light.