A Victorian reservoir under the long ridge of Helvellyn, made by damming and flooding two smaller lakes to pipe water to Manchester
Thirlmere looks like a natural lake, but it is a reservoir. In the 1890s Manchester Corporation dammed the valley and raised the water, drowning two smaller lakes and the hamlet of Wythburn to create a supply that still runs by gravity down a long aqueduct to the city, most of a hundred miles away. Dark conifer plantations line much of the shore, put in to protect the water, and the long whaleback of Helvellyn rises steeply on the eastern side — its summits fall within the Helvellyn & Fairfield reserve. A road runs down each side, there are car parks and forest trails, and Raven Crag at the northern end is a short, sharp pull up to a view over the water. This is a quieter, more wooded stretch of the Lake District than the southern lakes.
