The upland area is underlain by sedimentary rocks dating from the Devonian and early Carboniferous periods with Triassic and Jurassic age rocks on lower slopes. Where these reach the coast, cliffs are formed which are cut with ravines and waterfalls. It was recognised as a heritage coast in 1991. The highest point on Exmoor is Dunkery Beacon; at it is also the highest point in Somerset. The terrain supports lowland heath communities, ancient woodland and blanket mire which provide habitats for scarce flora and fauna. There have also been reports of the Beast of Exmoor, a cryptozoological cat roaming Exmoor. Several areas have been designated as Nature Conservation Review and Geological Conservation Review sites.