The first people to make a hilltop enclosure here were living in the Bronze Age at around 1,000BC. They dug banks and ditches to enclose a large six hectare area of the top of Cherhill Down.
In the Iron Age (500-100BC) it was extended to its current size of 9ha.
The hillfort is bivallate on most sides, having two banks and ditches, however, the north western side has only one bank as it is built on top of a steep escarpment which provides a natural defence.
Geophysical survey work carried out in 1996 revealed up to 20 circular features which are thought to be the remains of Iron Age round houses within the hill fort. These features, together with archaeological finds of animal bones, pottery and a weaving comb, all provide evidence that it was inhabited over 2000 years ago.
In the south west area there is evidence of disturbance which is likely to be that of quarrying for flint in the 18th and 19th centuries, possibly for the turnpiking of the Bath Road.
Over time paths and banks become eroded by walkers and livestock, to prevent further deterioration these areas are repaired by packing in sterile chalk often with the help volunteers.