 Part of the site was formerly a quarry where Totternhoe Stone, a strong type of chalk that was used in Westminster Abbey, was mined.This part is now grassland with a rich variety of plant species, including some that are now rare; these are characteristic species of chalk downland and include kidney vetch, horseshoe vetch, large thyme, squinancywort, autumn gentian, clustered bellflower, sainfoin and dwarf thistle.Orchids that grow here include common spotted orchid, bee orchid and twayblade.