Small but beautifully formed, these two caves are one of the island's biggest attractions, and justifiably so. Entertaining 45-minute tours lead you down steep steps; you get the benefit of a state-of-the-art lighting system that subtly illuminates the delicate straw stalactites and frozen stone waterfalls. Crystal Cave is the more striking of the two, with a pontoon walkway over shimmering waters that reveal more beautiful rock formations, as well as half a dozen cell phones that escaped slippery hands.

　　The two caves were discovered in 1907 by two teenagers who crawled down into subterranean darkness in search of a lost cricket ball.