Ingleborough Cave, was explored in 1837 by a Victorian land owner, who drained a underground lake to gain access. These days the cave is a well lit tourist attraction, with a path allow easy access past breath-taking stalagmites, stalactites and flowstones.
I was lucky enough to be invited along with Igers Yorkshire, for a guided tour through the caves before being opened to the public. More importantly this meant plenty of time for some long exposure photography!
Check out the websites for Ingleborough Cave , Ingleborough Nature Trail & Igers Yorkshire