The Iron Age hill fort at Old Sarum stands on the site of the first Salisbury cathedral, just north of the city of Salisbury and west of Castle Road (A345).
The Hillfort measuring 580 metres east-west by 460 metres north-south was erected around 400 bc, it shows evidence of Neolithic settlement and has been used as a Roman military station, a Norman bishops palace and cathedral (built around 1075-1092), and is now an English Heritage property, open to the public.
The earthworks are well preserved and comprise two banks and a medial ditch with two entrances, one on the eastern side which is approached by a causeway and one on the west side which is thought to be medieval in origin. The hillfort interior is convex. Excavations revealed occupation dating from the Iron Age until the beginning of the 4th century. The hillfort was originally an univallate enclosure with a possible northeast entrance but subsequently developed with bivallate defences, with the entrance now on the east side. Earthworks within the interior comprise two radial banks, with traces of a ditch on the west side. One of the banks is present to the south of the Medieval castle mound (SU 13 SW 149) the other to the north. The date of both earthworks is uncertain. The hillfort is Scheduled and in the care of the Secretary of State.
After the Norman conquest of England in 1066, William the Conqueror used Old Sarum, The Doomsday Book was partly written at Old Sarum.
Old Sarum. English Heritage Guidebook by John McNeill.
English Heritage, 2006 (paperback), 40 pages, ISBN 978-1850749813