The Clent Hills lie south-west of Birmingham city centre in Clent, Worcestershire, England. The closest towns are Stourbridge and Halesowen, both in the West Midlands conurbation (and also historically in Worcestershire). The Clent Hills range consists of, in order from north-west to south-east: Wychbury Hill, Clent Hill (and Adams Hill), and Walton Hill (and Calcot Hill). The north Worcestershire range of hills continues eastwards to include Romsley Hill, Waseley Hills and the Lickey Hills. Clent Hill is the most popular hillwalking hill in the range, although it is not often mentioned because the whole area is referred to as Clent Hills. Just under a million visitors a year are estimated to come to the hills, making them Worcestershire's most popular non-paying attraction. Geology The Clent Hills are a major outcrop of the Clent Formation consisting of Clent Breccia (predominantly a red-brown mudstone matrix) dating from the early part of the Permian period. The formation unconformably overlies the mudstones and sandstones of the Salop Formation which forms the lower ground to the north and east; both are assigned to the Warwickshire Group. The bedrock is cut by numerous faults, most of which are aligned NE-SW. Geography The hills along with the Lickey Hills form a range of hills in north Worcestershire known as the Clent-Lickey range (or the Clent-Lickey ridge). The largest of the Clent Hills is Walton Hill which is high followed by Clent Hill at . They are separated by a valley known as St. Kenelm's Pass, which starts as an escarpment one side of which along with the sides of the two hills falls away towards Uffmoor Wood; water flowing down this slope enters streams which become the River Stour. Close to the top of the escarpment, but just on the other side, stands High Harcourt Farm (which belongs to the National Trust, but its farm land is not open to the public). Below the farm the escarpment falls away and becomes a sharp V valley in which a stream flows down into Clent village. Where the valley sides are at their steepest the Walton Hill side of the valley is known as Clatterbach. In the past, before steam power replaced water power, the stream in the valley was dammed at regular intervals to provide power for watermills. The remains of one such dam can be seen behind the Vine Inn in Clent which was once a mill.