The third largest island in Thailand, Koh Samui is part of a trio of popular destinations in the Gulf of Thailand: Koh Tao has the best (and famously inexpensive) diving, Koh Phangan is infamous for its full-moon parties, and Koh Samui has the most refined beach-vacation atmosphere. Mid-range to upscale accommodations are the norm here, and the vibe is pure relaxation. Just about any treatment on earth is available, from the ubiquitous Thai massage to yoga retreats to weeklong detox cleanse regimens. The island has a few minor attractions—a 40-foot Buddha statue, a few jungle waterfalls, and some provocatively shaped rock formations. Throughout the years though, the culture has progressively catered to the Western traveler (if you’re looking for authentic Thailand, look on), with internet cafés, Starbucks, and knock-off clothing stalls.