The down is a 325.3 hectare biological and geological Site of Special Scientific Interest, notified in 1951.
The down has the best assemblage of sarsen stones in England, known as the Grey Wethers.
They were noted by Col. Richard Symonds in his diary for 1644: "They call that place the Grey-wethers, because a far off they looke like a flock of sheepe.
[2] On the west side of the down (grid reference SU12837150) is a recumbent sarsen stone with grooved markings.
[3] It is thought to be a prehistoric grinding bench for shaping, whetting, and polishing stone axe-heads, and is similar to other Neolithic and Bronze Age examples in France.