Ang Thong National Marine Park
45/1-2 Moo 1
You know those photos of dense jungle and white sand next to gigantic mountains jutting out of crystalline water? That’s the Ang Thong National Marine Park. This archipelago, made up of more than forty islands, is so bright and vivid, it looks Photoshopped. It's about an hour or two from Koh Samui (depending on the type of boat you choose; you can take a touristy slow boat, like the Red Baron, or a speedboat for the day). Depending on whether you take a private charter or a group tour, the local companies will tailor the day to what you're looking for, which will likely include some type of snorkeling, swimming, and trekking along the trails of a few of the inhabited islands (most are uninhabited).