Mam Tor stands right on the divide between the Dark Peak and the White Peak. It stands at the head of the Hope valley, with limestone to the south and gritstone to the north. The geology of the mountain gives it its distinctive appearance. The valley floor is limestone, which continues under the hill. The top of Mam Tor is millstone grit. Between them is a layer of soft shale, not capable of supporting the weight of the solid rock above.
The result is the Mam Tor landslip, which produces the dramatic east face of Mam Tor, and gives the mountain its nickname of the Shivering mountain. The landslide is still active, and more material falls off the cliff face every year. As late as 1979 the main road through Castleton continued on across the Mam Tor landslip. Twenty five years after being abandoned, the upper part of the road has simply disappeared!
Mam Tor is at its most impressive when seen from the Hope valley and the hills that surround it. From these viewpoints it dominates the scene. From Edale it is still impressive, but it becomes more obvious that Mam Tor is actually part of a ridge that curves around the end of the dale to Kinder, and is by no means the highest part of that ridge.
The summit of Mam Tor is enclosed within a bronze age hill fort. Due to the popularity of the hill, the path across the summit is now paved, to prevent erosion. Mam Tor has been a popular tourist destination ever since the Peaks began to be visited, featuring as one of Thomas Hobbes's seven wonders of the peaks of 1636.