Most visitors to Koror spend their days underwater and their evenings in town. The Belau National Museum and the Etpison Museum are both worth an hour or two to make sense of Palauan culture and the islands' tangled colonial history. The Palau International Coral Reef Center gives a useful primer on what you are about to see on the reef. Beyond that, walk the main road past the Sacred Heart Church, cross to Malakal for the marina and the small wrecks of Japanese boats still visible in the shallows, and book a boat to the Rock Islands — that is what you came for.