Wast Water

Wast Water or Wastwater is a lake in the Lake District National Park, England. The lake is approximately 4.6 kilometres (almost 3 miles) long and 600 metres (more than a third of a mile) wide, and is located in the Wasdale Valley. It is the deepest lake in England at 79 metres (258 feet), and is owned by the National Trust. It is one of the finest examples of a glacially 'over-deepened' valley. The surface of the lake is about 200 feet above sea level, while its bottom is over 50 feet below sea level.

The name of the lake and its valley is pronounced as in was, not with a hard a. The lake is named "Wast Water" on Ordnance Survey maps, but the spelling "Wastwater" is used with roughly equal frequency, including by its owner, the National Trust, along with the Cumbria Tourist Board, and the Lake District National Park Authority. The steep slopes on the south eastern side of the lake, leading up to the summits of Whin Rigg and Illgill Head, are known as the "Wastwater Screes" or on some maps as "The Screes". These screes formed as a result of ice and weathering erosion on the rocks of the Borrowdale Volcanic Group, that form the fells to the east of the lake, towards Eskdale. They are approximately 2,000 feet, from top to base, the base being about 200 feet below the surface of the lake.

The head of the Wasdale Valley is surrounded by some of the highest mountains in England, including Scafell Pike, Great Gable and Lingmell. Wast Water is the source of the River Irt which flows into the Irish Sea near Ravenglass. A popular path runs the length of the lake, through the boulders and scree fall at the base of this craggy fell-side. On the north western side are the cliffs of Buckbarrow (a part of Seatallan) and the upturned-boat shape of Yewbarrow.