Gaping Gill

Gaping Gill (also known as Gaping Ghyll) is a natural cave in North Yorkshire, England. It is one of the unmistakable landmarks on the southern slopes of Ingleborough – a 98-metre (322 ft) 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 freefall waterfall in the UK and the largest underground chamber naturally open to the surface.

Cave data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).