Surat Thani's other major draw sits a stone's throw from Samui. In fact, you can see one from the other's shores. Koh Phangan is where the monthly Full Moon Party is held, an event that overshadows the islands more genteel charms. While it is advisable to avoid Haad Rin, the Full Moon beach, there are many beautiful locations on the island that offer quiet, respite, and great underwater exploration.