Gower is also home to menhirs or standing stones from the Bronze Age. Of the nine stones, eight remain today. One of the most notable of the stones is Arthur's stone near Cefn Bryn. Its 25-ton capstone was most likely a glacial erratic (a piece of rock/conglomerate carried by glacial ice some distance from the rock outcrop from which it came): the builders dug under it and supported it with upright stones to create a burial chamber. The remains of Sweyne Howes on Rhossili Down, Penmaen Burrows Tomb (Pen-y-Crug) and Nicholaston Long Cairn are three other well-known Neolithic chambered tombs. During the Bronze Age, people continued to use local caves for shelter and for burying their dead. Bronze Age evidence, such as funeral urns, pottery and human remains, has been found in Tooth Cave at Llethryd, Culver Hole (Port Eynon) and Cathole Cave. With the transition into the Iron Age, hill forts (timber fortifications on hill tops and coastal promontories) and earthworks began to appear. The largest example of this type of Iron Age settlement in the Gower Peninsula is Cilifor Top near Llanrhidian.