Much of central Dartmoor is an uninhabited wilderness almost free of villages, farms, trees and roads making it outstanding environmental value. From this mass rise Dartmoor's rivers, including the Lyd, Tavy, East and West Dart, Bovey, Teign, Taw and Okement, nearly all of which flow southwards to the English Channel. The large numbers of tors that dominate Dartmoor are the remnants of hard masses of granite, drastically reduced in size and moulded into their present shapes by millions of years of weatherings. Bowerman's Nose, Hound Tor and Haytor Rocks are famous examples included on these walks.