Cadbury Castle, Somerset

Cadbury Castle is an Iron Age hill fort near the village of South Cadbury in Somerset, England, five miles north west of Yeovil at grid reference ST62862512. As the only contemporary fort large enough to host an army, it is one of the best known of the sites associated with mythic Arthurian England, and the legends of Camelot. The summit is 150 metres (500ft) above sea level, and the hill is surrounded by four terraced earthwork banks and ditches and a stand of trees. Excavation at and around the site has discovered Iron Age, Roman and Saxon artifacts. The excavation was lead by archaeologist Leslie Alcock from 1966-1970. The limestone hill is situated on the southern edge of the Somerset Levels, with flat lowland to the north.
Note: there is also a Cadbury Castle at grid reference SS91310528 in Devon.
Prehistoric hill forts in Britain are often traditionally named 'Castle' (such as Maiden Castle, Lambert's Castle and Membury Castle). This name refers to the defensive earthworks, and does not mean that there was any building of the type more commonly thought of as a castle on the site.