Mae Koh (Mother Island) is one the most visited of the 42 islands that make up the Mu Ko Ang Thong National Park, which is situated in the Gulf of Thailand, in the Surat Thani Province. The main attraction on the island is Emerald Lake, a saltwater lake linked to the ocean via an underground tunnel and surrounded by karst limestone walls and lush green foliage. A rather steep climb along pathways and a wooden staircase will reward visitors with a full view of this stunning body of emerald-green water. The island also boasts spectacular white, sandy beaches and the waters around the island are well-populated with tropical fish, sea turtles, and other marine life making it popular with snorkelers. The island is easily reached by speedboat from any of the neighbouring islands and day tours are on offer.