Diamond Cave / Phra Nang Nai Cave

This guide to Diamond Cave above Railay opens with a two-hundred-baht cash payment at a national park booth and the arithmetic that never quite settles about what that fee is actually meant to be. It follows the only way in, by longtail boat with no road to check the signage against, and up a patched bamboo and timber walkway into rock that has been catching drip water since long before anyone thought to charge for it. Keep a hand off the rail near the ceiling, where bats roost overhead.