Pastscape lists Backwell as a probable Iron Age promontory hillfort. It was originally spotted from the air, before being investigated on the ground in 1933. Much of it has been destroyed by quarrying (you can see this plainly in the satellite image above). E.K Tratman, the Somerset archaeologist, excavated the cave site at Backwell hill, discovering some very interesting Iron Age (and other) material in the process. His report of the dig – The Excavation of Backwell Cave, Somerset – is hosted at the excellent U.B.S.S website.
Although it was described as being nearly destroyed by 1956, and completely destroyed by 1962, a small section was reported as having beeen located in 1979. The full Pastscape page for Backwell Hillfort can be found here.

Location

OS map reference: ST 4940 6805 . Nearest town/village: Backwell.