The wind grew so strong as we crested the moor that a meadow pipit, startled into the air at our approach, squeaked once and immediately buried itself again in the heather. One of our party thought it prudent to put on snow goggles to keep his eyes from watering and his view unrestricted. It was an unusual look for a Derbyshire hillside, but I soon envied him. At Cowms Rocks I found I could lean at a sharp angle into the gale while taking in the view of Kinder Scout’s proud and craggy ramparts across the Ashop Valley to the south. It was a different story at my feet. Below Cowms, the land has slumped, like a geological sandwich cake dragged from the oven too soon, leaving a lumpy green depression sprinkled with grey rocks that have worked loose from the surrounding slopes. The southern Pennines is a hotspot for such landslips: a similar feature in the neighbouring valley of Alport is often cited as the largest in Britain. While this part of the Peak District remained beyond the southern limit of the last period of glaciation, it was still permafrost, and the melting of its frozen rocks, layers of sandstone and weaker shales prompted a dramatic settling of the landscape. What’s more, it isn’t over. As we walked east, shoulders hunched against the wind, we came upon a vast new crevasse in the moor’s brink. Ten years ago, this was little more than a crack in the surface. Now it has widened and deepened, up to 40ft (12 metres) in places, and has extended itself more than a hundred yards along the moor’s edge, and most recently over it. The edge of this chasm overhung in places, and in others new splits were forming further back, threatening the unwary with a fast trip to the bottom. Near the surface, hard ferns glowed greenly, but deeper down all was wet mud and glistening rocks. Braiding rivulets of water revealed that it’s heavy rain and snow melt that trigger such movements. The “timeless mountains” are always on the move.