This underground cave system was discovered by two local men in 1912—make that rediscovered, as one of the caves contained 42 human skeletons that had lain undisturbed for around 7,000 years. The main cave system, Dan Yr Ogof (Welsh for "beneath the cave"), is an impressive natural wonder, particularly the Cathedral Cave with natural stone archways and a dramatic waterfall. The whole thing is pitched at kids, with "dramatic" piped music to "enhance" the atmosphere, and a park featuring 200 life-size models of dinosaurs and other prehistoric creatures. There's also a playground, petting zoo, shire horse center, and Victorian farm complete with costumed craftspeople and other "how we lived then" shenanigans. The caves are 17 miles southwest of Brecon.