Belbury Castle is an Iron Age earthwork roughly 3 kilometres southwest of Ottery St Mary, consisting of a roughly oval enclosure defined by earthen ramparts and ditches. It sits on a low ridge in the rolling East Devon farmland and is thought to date to the late Bronze Age or early Iron Age, perhaps 800–400 BC. The site is unexcavated and little studied, which gives it a pleasingly wild feel — the ramparts are overgrown with trees and scrub, and the interior has reverted to rough pasture.
The site can be reached on foot from Ottery along the network of public footpaths that cross this part of Devon. It is not signposted and takes a little navigation to find, but the walk through the hedgerow-bound lanes and fields is pleasant in itself. There is no formal access or interpretation, and the earthworks themselves are unimpressive compared to better-known Devon hillforts like Hembury or Cadbury Castle, but for those interested in the pre-Roman landscape of East Devon it is worth seeking out.