Treryn Dinas

Treryn Dinas is an Iron Age promontory fort on a granite headland near Treen in Cornwall, England, owned by the National Trust and designated as a Scheduled Monument. Its defenses consist of three sets of large ramparts and ditches, the largest measuring nearly 20 feet high and 800 feet long. Excavations by the West Cornwall Field Club in 1939 and 1948-49 uncovered pottery dated to 800-400 BC and remains of two small roundhouses. The headland is also famous for the Logan Rock, a naturally balanced 65-ton boulder perched 100 feet above the sea.