Maiden Castle is an Iron Age hill fort 1.6 miles south west of Dorchester, in the English county of Dorset. Hill forts were fortified hill-top settlements constructed across Britain during the Iron Age.
The earliest archaeological evidence of human activity on the site consists of a Neolithic causewayed enclosure and bank barrow. In about 1800 BC, during the Bronze Age, the site was used for growing crops before being abandoned. Maiden Castle itself was built in about 600 BC; the early phase was a simple and unremarkable site, similar to many other hill forts in Britain and covering 6.4 hectares. Around 450 BC it was greatly expanded and the enclosed area nearly tripled in size to 19 ha, making it the largest hill fort in Britain and, by some definitions, the largest in Europe. At the same time, Maiden Castle's defences were made more complex with the addition of further ramparts and ditches. Around 100 BC, habitation at the hill fort went into decline and became concentrated at the eastern end of the site. It was occupied until at least the Roman period, by which time it was in the territory of the Durotriges, a Celtic tribe.