It is situated on the North Downs and the chalk grassland slopes of the park are a Site of Special Scientific Interest. These slopes were formerly used as grazing for farm animals, but were left to naturalise after the farms moved to the lower and more productive wealdland pastures. After the park was formed, these grasslands were cleared of scrub to allow the rare chalk land plants and animals to re-establish including the musk orchid, and chalkhill blue butterfly. Other meadow insects found include the dark green fritillary.