Famed as a divers' paradise, this small island north of Ko Pha Ngan and Samui is often overlooked by non-divers - and wrongly so. It's a beautiful, tranquil, wooded isle with dense palm- and rain-forests in the interior, and 20km of coastline hiding a succession of secluded coves protected by vast granite boulders.
Koh Tao means 'Turtle Island', named after the sea turtles who breed here, and also apparently because of its shape (though frankly we have never seen such a wonky-looking turtle!). Of course the marine life is spectacular, particularly around the triple coral islets of Nangyuan, off northern Koh Tao. Hawksbill turtles, giant barracuda, porcupine pufferfish, butterfly fish, triggerfish, whale sharks (seasonal), bat fish and stingrays are some of the highlights. There are 25 recognised dive sites - pinnacles, coral gardens, canyons, swim-throughs, chimneys - within 1km of the coast, around 15-30m in depth. But if you fancy staying above water, scenic boat trips, sea kayaking and wonderful hiking are all available, too.