Ko Samui, Thailand’s second largest island, lies in the Gulf of Thailand off the east coast of the Kra Isthmus. It's known for its palm-fringed beaches, coconut groves and dense, mountainous rainforest, plus luxury resorts and posh spas. The landmark 12m-tall golden Big Buddha statue at Wat Phra Yai Temple is located on a tiny island connected to Ko Samui by a causeway.