The site is underlain by Clifton Down Limestone, Burrington Oolite, Black Rock Dolomite and Black Rock Limestone of the Carboniferous Limestone Series. There is dolomitic conglomerate (Triassic Mudstone) at the lower edges of the site. The site has unimproved calcicolous grassland, some of which is mixed with dwarf-shrub, mosaics of calcicolous grassland and scrub and woodland. Four nationally rare types of vegetation form most of the grassland. Rare species include Koeleria vallesiana (Somerset hair-grass), Carex humilis (dwarf sedge) and Potentilla tabernaemontani (spring cinquefoil).English Nature citation sheet for the site (accessed 16 July 2006)
