Nusa Penida, off the southeast coast
Look southeast from the beaches at Sanur and you can see it on the horizon: a long, high island of white limestone, bigger than it looks and, until a decade or so ago, almost entirely ignored by visitors. Nusa Penida is still raw. Its roads are rough, its interior is dry scrub and cassava fields, and its coastline is a run of sheer cliffs that drop hundreds of feet into some of the clearest, bluest water in Indonesia. It is a different island from Bali in every way, and a day here is the wildest thing you can do within an hour of the resorts.
The fast boat from Sanur takes about 45 minutes, and a private driver meets you at the pier for a loop of the west coast. Kelingking is the headline, a knife-edge ridge of cliff shaped unmistakably like a dinosaur's head, with a white crescent of beach far below and the ocean a blue that does not look real. Nearby, the sea has carved the coast into the natural stone arch of Broken Beach and the tidal pool at Angel's Billabong, and at Crystal Bay a quiet cove of pale sand and coconut palms gives you the island's easiest swim, with corals a short swim from the shore.
Then there is what lives in the water. The channel off Penida's southwest cliffs is a cleaning station for reef manta rays, and snorkeling at Manta Point, with these gentle animals gliding beneath you on wingspans of twelve feet or more, is one of the great wildlife encounters in Southeast Asia and possible most of the year. We build Penida as a long day from the southeast coast with the boat timed for calm morning seas, or as an overnight on the island or on gentle Nusa Lembongan next door, which puts you at the cliffs before the day boats arrive.