Knollbury is a scheduled neolithic enclosure to the north west of Chadlington in Oxfordshire. Believed to be defensive in nature the enclosure is rectangular (100 metres by 150 metres) formed by a 2-to-4-metre-high (6.6 to 13.1 ft) and 10-metre-wide (33 ft) earth banks. The two gaps in the earth banks at the eastern corners are believed to be of a later date.