Wakehurst and Chiddinglye Woods have been designated as a SSSI because of the extensive exposure of sandrock - a geological important and nationally rare habitat. The site has the richest sandrock community in the country, supporting unique flora, the uncommon cranefly, and a diverse breeding community of woodland birds. The owner of the outcrop has (with the support of Natural England) has banned climbing – access is only available to groups with legitimate scientific interests who apply in writing beforehand.