The limestone hills around the smal village of Bau are holed like a Swiss cheese. Most caves are hidden and should only be explored with proper caving equipment, but two caves are easily accessible, namely the Fairy Cave (picture) and the Wind Cave, about 6 km apart outside the village of Bau.
The Wind Cave (Gua Angin) has its fair share of stalagmites, stalactites, and pillars, but is particularly known for swiftlets and bats. A boardwalk runs the length of the cave, while a small river meanders at the bottom. A cool breeze blows, earning the name to the cave.
The Fairy Cave (Gua Kapor) is a totally different story. The cave entrance is 30 metres up, accessible through a flight of stairs in a concrete tower. The cave has been a place for prayer throughout times and there are several shrines in here. The cave is huge, a lot bigger than the Wind Cave, and though there are boardwalks here too (well, concrete stairs), you can go exploring the dark parts on your own. Just remember to bring a flashlight.