MALAYSIA / Located 36km (22 miles) off Sabah's southeast coast, Sipadan sits atop an extinct volcanic cone surrounded by near-vertical walls. Blanketed in technicolour corals, they form a veritable way station for all types of sea life, from barracuda to bumphead parrotfish and, from around March to May, whale sharks. Sea turtles and reef sharks are a given during any dive, and divers might also spot mantas, eagle rays, octopus and scalloped hammerheads. Book ahead - only 120 Sipadan passes are issued each day.