Stand on Whitestone Cliff and you will look down upon Gormire Lake - a fascinating remnant of the last Ice Age.
James Herriot once called this view 'the best in England' - and the vista in the North York Moors includes one of Yorkshire's four natural lakes.
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Surrounded by forest in the valley bottom, Gormire was formed by glacial erosion over 20,000 years ago and has been shrouded in mystery ever since.
Gormire has no major inflow or outflow of water - confounding people who wondered how the lake was fed. Modern scientists believe the water supply comes from an underground spring, but hundreds of years ago its existence seemed magical.
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The name 'Gormire' translates as 'filthy swamp', and it is also sometimes known as the White Mere.
Its dark appearance gave rise to several myths, including that it is bottomless and conceals the submerged remains of a sunken village.
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Visitors report that the lake and Garbutt Wood, which encroaches right up to the shore, have an 'otherworldly' and 'fairytale' quality.
Nowadays, it's a popular spot for wild swimming - The Times even named it as one of the UK's 20 best natural swimming locations. The lack of a water supply means that the lake is calm and still, with warm temperatures - although there's an abundance of leeches.
There's a visitor centre at nearby Sutton Bank and the area is also a great vantage point for views of Roulston Scar, an Iron Age hill fort which once covered 60 acres and was one of the largest in the country. It's now used as a launch site for gliders.