Thian Og Bay (or Ao Thian Oh)
Ao Thian Og leaves most of the other beaches on Koh Tao back at the starting post in terms of sheer beauty. The perfect arc of white, fluffy sand and azure waters will leave you breathless. Almost always quiet and serene, this is the perfect place to chill out for an afternoon.
The beach has shade from shrubs rather than trees and is empty much of the time despite its proximity to Chalok Baan Kao. While people stay away, sharks flock here, however: it's a popular bay with divers.
One of the newest and flashest resorts on Koh Tao, Jamahkiri, has a monkey enclosure, ensuring the peculiar calls of primates now ring out regularly across the bay.
Ao Thian Og is separated from Chalok Baan Kao by a peninsula, and on the eastern flank of this peninsula, facing Ao Thian Og, you'll find Ao Taa Chaa which has good snorkelling and a couple of very well-appointed resorts perched on its edge.
If you walk out to the end of the peninsula you'll reach the John Suwan Viewpoint, a spectacular vantage point overlooking Ao Chalok Baan Kao to the left and Ao Thian Og to the right. Unfortunately the trail hasn't been well looked after, so it's quite a bush-bash to get there nowadays.
Further to the east you'll find the very pretty Haad Sai Daeng where, just offshore, sits Shark Island - one of Koh Tao's most popular dive spots. The bay itself has some fine snorkelling when the water is calm and there is also more than enough sand to just lay around or plan out world domination or another frisbee-golf course.
While it's a shame that Coral View Resort decided to build a two-storey building right on the beach, the beach nevertheless remains scenic and relatively low key. It's a good choice for those looking for some peace and quiet but who don't want the absolute isolation you'll get on the east coast beaches.
Chalok Baan Kao is close enough to be an option for an evening out but if you don't want to wander that far, there are a couple of places to eat at on Sai Daeng itself.