Gaping Gill

Gaping Gill is a natural cave in North Yorkshire, England. It is one of the unmistakable landmarks on the southern slopes of Ingleborough – a 98-metre deep pothole with the stream Fell Beck flowing into it. After falling through one of the largest known underground chambers in Britain, the water disappears into the bouldery floor and eventually resurges adjacent to Ingleborough Cave.

The shaft was the deepest known in Britain, until Titan in Derbyshire was discovered in 1999. Gaping Gill still retains the records for the highest unbroken waterfall in England and the largest underground chamber naturally open to the surface.

Source: Wikipedia