The Derwent Valley Skyline is a demanding Dark Peak circuit in the Peak District National Park, linking Ashopton, Crook Hill, Alport Castles, Alport Moor, Bleaklow Stones, Bleaklow Head, Featherbed Moss, Margery Hill, Outer Edge, and Back Tor. A 46–50 km moorland expedition with relentless navigation, bogs, peat hags, groughs and featureless terrain, it tests endurance across one of the UK’s most remote-feeling upland landscapes.