An ancient communications route following the line of an upland ridge. these are tracks along the watersheds from hillfort to hillfort, used by prehistoric man. Often there is no artificially constructed roadway, but some routes became Roman roads or medieval droveways. The dates of the finds extend back beyond the Middle Ages. Important British ridgeways are the Jurassic Way along the limestone ridge from Dorset to Lincolnshire, the Icknield Way in the Chilterns, and the Pilgrims' Way along the North Downs.