Pentre Ifan
The dolmen dates from about 3,500 B.C. It may have been used for group burials. The existing stones form the door, called a portal and main chamber of the tomb. These would have been covered with a large stone mound about 36.6 m long and 17 m wide. Some of the stones have been scattered, but at least seven are in their original position. The capstone is 5.1 m in length, and is thought to to weigh 16 tonnes, and rises 2.4 m above the ground. It is held up by the narrow tips of three uprights. These stones make a chamber that is 3 m long, 2 m wide and 3 m high. A large stone has been used to block the entrance.