Sri Thanu is a small volcanic peninsula on the west coast of Koh Phangan, just five minutes from the ferry port at Thong Sala. A coral reef sits just offshore, within easy swimming distance from the beach — bring a mask and you'll see plenty.
The bay is quiet compared to the party beaches further south. A handful of bungalow operations line the shore, and a small yoga and wellness scene has taken root here without overwhelming the place. The sunsets over the Gulf of Thailand are particularly good from this stretch of coast.