With its white-sand beaches hemmed in by coconut palms, private beach resorts reachable only by boat, and swathes of lush rainforest; Koh Samui comes as close to paradise as anywhere in Thailand. Marooned off the Gulf of Thailand coast and reachable by ferry from Chumphon and Surat Thani, Samui island is the largest of the Chumphon archipelago, and ranks second only to Phuket for the title of Thailand’s most visited island. On the east coast, Chaweng beach is the island’s party hub, lined with beach bars, nightclubs, and 5-star resorts, while Lamai Beach, Choeng Mon Beach, and Bophut offer more laid-back alternatives. Away from the beach, dramatic viewpoints abound, with highlights including Na Muang Waterfall, the Hin Ta and Hin Yai rocks, and the dazzling gold façade of Big Buddha Temple (Wat Phra Yai). The island also makes a popular basecamp for exploring the surrounding islands and speedboats plow the route between Koh Phangan, host of Thailand’s notorious Full Moon parties, and Koh Tao, a popular scuba diving and snorkeling spot. Off the west coast, a sea kayaking or snorkeling tour of Ang Thong National Marine Park—a cluster of jungle-clad islands, ringed by jagged rocks, sandy coves, and a rainbow of coral—is perhaps the most enchanting option for a day trip.