Hollingbury is an area of the city of Brighton and Hove, East Sussex. The area sits high on a hillside across the north of the city, east of Patcham which lies in a valley to the west, Coldean in a valley to the east, and the A27 bypass forming the northern limit. To the south it blends into the leafy Surrenden area and the busy Fiveways local shopping area. Hollingbury Hill itself reaches an elevation of above sea level and on the summit is Hollingbury Castle Camp, an Iron Age hill fort dating from around the sixth century B.C. It is where Triangulation Point (or Trigpoint) TP3970 used for the 1936 Ordnance Survey mapping of Great Britain is located. The north-western slopes of the hill have been developed and are populated with housing dating from the 1940s onwards with minor retail and industrial use. The building of Hollingbury housing estate, located on the north-western slopes of the hill, commenced in 1946. The development is a mixture of bungalows, flats and houses with most of the earlier properties having large gardens. Some properties were originally owned by the local council and some were privately owned although a large number of the local council ones have since been sold. Some roads (Westfield Crescent for example) contained clusters of houses for use as armed forces or police service housing. Most of these have been sold and are now privately owned. The housing is divided by small parades of local shops which are located throughout the estate along with some public houses. The estate is the town's largest post-war (World War II) council estate and is built on land originally acquired by the council in November 1909. The most notable part of this area Hollingbury Castle or hill fort (). It is to the east of Hollingbury housing estate and the Ditchling Road, Although considered the Castle to be Iron Age, the mounding of four round barrows suggests even Bronze Age people held this place sacred. Now all that remains are thickets of gorse which shine yellow in spring and are home to linnets and goldfinch.