A small island twenty minutes by boat from the main village, Menjangan Besar holds the islands' only sanctuary for blacktip reef sharks — a controversial pen built into a shallow lagoon where visitors can wade in the water with the sharks for a fee. The conditions for the animals are debated locally; many tour operators have stopped including the pen for ethical reasons.
The rest of the island is more straightforward — clean white sand on the eastern side, decent shallow snorkelling, and a small village. Stop here for a few hours as part of a multi-island day trip.