I guess this counts as "The Natural Side of the Underwater World", geologically speaking.
Went to Bolton Abbey today, and have become fascinated by the section of the Wharfe river known as The Strid. For those that don't know, this is a section of some 25 metre wide river that flows through a rock restriction that is barely 2 metres across (in places, at the surface) for about 30-40 metres, before emerging once again into wider, shallower waters. Now, even my pea-sized brain can work out that the Strid must be deep, and hollowed-out, to carry that amount of water through it, and it is undoubtedly as dangerous a stretch of water as might be imagined.
Having returned home and scoured the net for more information, all I've found is tabloid folklore and accounts of the deaths of those who have inadvertently fallen in whilst trying to leap across the seemingly innocent gap. But I want to know what lies beneath.
Does anyone know whether a proper geological survey has been carried out here? The sign nearby has a pictorial silhouette of a diver in what presumably is an artist's impression of a 9 metre deep cross-section. Probably a difficult thing to do in peat-stained fast flowing water, but this must be possible these days?
I need to know!