Mam Tor - the Shivering Mountain - is a mountain pass at an elevation of 461m (1,512ft) above the sea level, located near Castleton in the High Peak of Derbyshire, England.
The road to the summit is paved, with some steep parts. The narrowness of the road and its 20% (1 in 5) gradient has caused it to be closed to buses, coaches and vehicles over 7.5 tonnes in weight. The road winds through a cleft, surrounded by towering limestone pinnacles. Frequent landslips on its eastern face have resulted in a multitude of 'mini-hills' beneath it. These landslips, which are caused by unstable lower layers of shale, also give the hill its alternative name of Shivering Mountain.
The road features regularly in the Tour of the Peak cycle race each autumn. It presents the riders with a severe challenge, and often determines the race outcome. In 1979 the continual battle to maintain the A625 road (Sheffield to Chapel en le Frith) on the crumbling eastern side of the hill was lost when the road officially closed as a through-route. There are 3 possible routes to reach the summit. Starting from Edale, the ascent is 3 km long. Over this distance, the elevation gain is 317 meters. The average percentage is 10.6 %. Starting from Chapel en le Frith, the ascent is 8 km long. Over this distance, the elevation gain is 317 meters. The average percentage is 4 %. And starting from Edale, the ascent is 3.29 km long. Over this distance, the elevation gain is 219 meters. The average percentage is 6.6 %.