Kielder Water is a reservoir, finished in 1982, and it is the largest artificial lake in northern Europe by capacity. Around it is Kielder Forest, 250 square miles of mostly Sitka spruce, the largest working forest in England. It feels much wilder than that sounds: red squirrels, ospreys nesting by the water and hardly any light at night.
Kielder is the heart of the Northumberland International Dark Sky Park, and Kielder Observatory, on a hill above the forest, runs stargazing evenings almost every night of the year; book well ahead. By day the Lakeside Way, a 26-mile trail around the water, is good for cycling. Mountain bikers come for the forest trails, and there is sailing and kayaking on the lake. Along the shore stand a series of large outdoor artworks and buildings, including James Turrell's Cat Cairn: The Kielder Skyspace.
It is a long way from anywhere, about an hour and a half from Newcastle by road, and there is no train.