Bac Lava: Perhaps the wildest swim in the Lake District, at 284m Wastwater is England's deepest lake. It's three miles long and has the ominous scree slope of Scafell Pike, England's highest mountain dropping directly into the water on the east side. It's an awe inspiring swim: from the water there are 360 degree view of water, mountains and rocks.
The lake has a sensitive shoreline and is a special area of conservation, so motor boats are not allowed, although expect to see a few canoes (the limit is 12 boats at any time) which launch from designated locations. There is a National trust campsite at the Wasdale Head end of the lake, and a Youth Hostel at the other.