Extensive networks of caves have developed within the limestone strata such as the White Scar Caves, and potholes which attract cavers from all over the country. It is home to England's highest waterfall at Gaping Gill, where the Fell Beck drops vertically down a pothole, into Britain's second largest cavern. The beck re-emerges further down the mountain adjacent to Ingleborough Cave, where visitors can take a guided tour of a floodlit part of the cave system. Whernside, being more rounded, is visually less imposing than its neighbours, but its summit is the highest point in North Yorkshire.