On the grassy 1695-foot summit of Mam Tor, dominating the head of the Hope Valley two miles north-west of Castleton, are the earthwork remains of an Iron Age hillfort. Covering 16 acres, it stands on the site of a Bronze Age settlement dating back to over 1000 BC, and is the largest hillfort in the Peak District.
Known to the Celts as the "Mother Mountain", Mam Tor is connected to the 1563-foot Lose Hill by an ancient track which runs along the crest of a sandstone and shale ridge.
Because of the instability of the sedimentary rocks, the slopes of Mam Tor are constantly crumbling (hence its popular name, the "Shivering Mountain"). At some time in the past a large section of the hill slipped away leaving the sheer, exposed face visible today. In 1979, two years after a dramatic landslip, the Mam Tor section of the old A625 trans-Pennine road was permanently closed because much of it had disappeared down the slope. The remains of this old road can be seen in the right foreground.
