Bau, about 45 minutes from Kuching, was a 19th-century gold-mining boomtown, and the limestone hills that made it geologically interesting for miners also happen to hold two of the most easily visited caves near the city. Fairy Cave is reached by a short climb up a stone stairway into a huge, high-ceilinged chamber where sunlight filters down through gaps in the rock, lighting moss and stalactites in a genuinely otherworldly green.
A small Chinese altar sits inside Fairy Cave, tended by local visitors, and rock climbers know the surrounding cliffs for some of the best limestone sport routes in Sarawak. Not far away, Wind Cave is a cooler, wetter counterpart — a network of tunnels and underground streams named for the natural draft that runs through it, home to bats, swiftlets and, if you're lucky with timing, a resident troop of long-tailed macaques at the entrance.
Both caves are easy half-day additions to a Kuching itinerary, usually paired with a stop in Bau town itself or the nearby Jagoi Bidayuh heritage sites — no serious caving gear required for either.