Nang Yuan Island, near Koh Tao in Surat Thani, Thailand, is a quintessential destination known for its stunning viewpoints and clear turquoise waters ideal for snorkeling and diving. Best accessed by a short boat trip from Koh Tao, the island welcomes visitors during the dry season, from late December to April, to avoid the monsoon. A small entry fee is charged, which typically includes the cost of a day trip. Tours are recommended for first-time visitors to make the most of snorkeling sites, though independent visits are possible. Plan for half a day to explore and enjoy the local café. Remember that the island enforces strict environmental rules, including a ban on single-use plastics and a stipulation not to wear sandals to protect its unique ecosystems.