Haweswater is a reservoir in the Mardale valley supplying water for the urban conurbations of north-west England. Originally it was a natural lake about four kilometres long, almost divided in two by a tongue of land at Measand. Prior to the valley being flooded in 1935 all the farms and dwellings of the villages of Mardale Green and Measand were demolished, the village church was dismantled and the stone used in constructing the dam. All the bodies in the church yard were exhumed and reburied at Shap. Today when the water in the reservoir is low, the remains of the submerged village of Mardale Green can still be seen as stone walls and the village bridge become visible as the water level drops.

To the west of Haweswater is the Riggindale valley, the only known place in England where Golden eagles nest. A pair of eagles first nested in the valley in 1969 and although the male and female of the pairing have changed several times, sixteen chicks have been produced. The last female disappeared in 2004 leaving the male on its own. However, it is hoped that a replacement female will be drawn to the area. It doesn't help that the male rarely ascends above the level of the ridges around - maybe he just likes the peace of "his" valley.

Like all the large lakes it is difficult to get a good view of the whole lake, indeed there is no vantage point where all of Haweswater is visible because of the curvature of the valley. However, good views are possible from the High Street ridge to the west or, for the less strenuous, from Riggindale or The Rigg. Footpaths run all around the lake and there is a small car park at Mardale Head, a good starting place for walks to the RSPB eagle viewpoint in Riggindale and to the High Street ridge.