Arbury Banks, Hertfordshire
It was probably first constructed during the late Bronze Age, 1000-700 BC. Standing at 90m above sea level, it is one of a line of six similar hill forts along the northern Chilterns that includes Wilbury Hill Camp southwest of Letchworth. Excavations in the 1850s traced Arbury Banks' horseshoe-shaped ramparts and identified two opposed north-north-west and south-south-east entrances. Evidence was also discovered for several enclosures or buildings inside the fort.