Pentre Ifan is a splendid burial chamber with a huge capstone delicately poised on three uprights. Once known as Arthurs' Quoit, Pentre Ifan means Ivan's Village. Dating back to about 3500 BC and unusually oriented north-south, it stands on the slopes of a ridge commanding extensive views over the Nevern Valley. The capstone weighs over 16 tons; it is 5m (16ft 6in) long and 2.4m (8ft) off the ground. The stones of the chamber are all of local igneous rock; on the portal stone there is a faint decorative cupmark.