On their south side the moors are demarcated by a series of dales which drain into tributaries of the River Derwent. The westernmost dale is Rye Dale, to the west of which rise the Hambleton Hills. Bilsdale is a side dale of Rye Dale. East of Bilsdale Bransdale, Farndale, Rosedale and Newton Dale cut into the moors. In the south east, the landscape is marked by the narrow valleys of the upper reaches of the Derwent and its upper tributaries.