Waggoner's Wells in Hampshire consists of three man-made ponds/lakes, which were created in the 17th century by the Hooke family of Bramshott. With evidence of ironmaking in the area, it's believed they were originally intended as hammer ponds, which would have provided water to power machinery used to produce iron, but they appear never to have been used. It's been suggested that they instead served as fish ponds.
Devil’s Punch Bowl
The Devil’s Punch Bowl, part of the Hindhead Commons, is a large natural amphitheatre near Thursley and Hindhead, which is a Site of Special Scientific Interest and managed by the National Trust.