Ko Adang is around 30 sq km (12 sq miles) in area, and is almost completely covered in tropical rain forest. The island is famous for its clear waters, fine quartz beaches and superb coral reefs, the latter providing a habitat for shoals of brightly-colored fish and a host of other marine creatures. The interior of Ko Adang is also beautifully pristine, with several waterfalls cascading down from the central heights (703 m3t34w or 2,300 ft), most notably Nam Tok Chon Salat. Ko Tarutao Marine National Park consists of 51 islands in two main groups scattered across the Andaman Sea in southernmost Thailand. Just seven of the islands are of any size, including Ko Tarutao in the east, and Ko Adang-Ko Rawi to the west. Just 5 miles (8km) to the south lies the marine frontier with Malaysiaˇs celebrated Langkawi Archipelago. Tarutao is world-famous for its pristine diving sites, rich marine life and outstanding natural beauty. Covering a broad area of 575 sq miles (1490 sq km), Tarutao became Thailandˇs second national marine park in 1974. Because of the location of the islands so far out to sea, the park is only safely accessible during the northeast monsoon between November and April.