Mauke's most adventurous cave, on the eastern coast. A series of low limestone chambers connect, several with their own freshwater pools, and the system eventually opens onto the reef — at low tide you can swim out through the seaward entrance. Local legend gives it a hundred rooms; the reality is closer to seven or eight, but the labyrinthine feel is real.
Go only with a guide from one of the guesthouses and only at the right tide. Headlamp, reef shoes, and willingness to crawl on hands and knees through one short section are all required.