Mole Gap to Reigate Escarpment and there are well developed river cliffs where alluvial fans have diverted the River Mole against the valley sides. Mole Gap to Reigate Escarpment Mole Gap to Reigate Escarpment is a biological and geological Site of Special Scientific Interest west of Reigate in Surrey. It is a Geological Conservation Review site and a Special Area of Conservation. Part of it is a Nature Conservation Review site, Grade I. Two small private nature reserves in the site are managed by the Surrey Wildlife Trust, Dawcombe and Fraser Down. This eight mile long site on the North Downs contains an outstanding range
River Mole Ages and the river appears as "Amele" in Domesday Book and subsequently as "Emele" in 12th- and 13th-century Court Rolls. This name is probably derived from the Old English word "æmen" meaning "misty" or "causing mists", and the name of the River Ember probably has its origins in this name. The name "Mole" does not appear until the 16th century, first occurring as "Moule" in Harrison's "Description of Britain" of 1577. The antiquarian William Camden uses the Latinized form "Molis" in the 1586 edition of "Britannia" and Michael Drayton is the first to use "Mole" in his poem "Poly-Olbion" published