Ang Thong National Marine Park
Ang Thong National Marine Park comprises over 40 more islands northwest of Samui and is well known for its scenic beauty and coral reefs. Many of these islands are limestone rock towers of up to 40m (131 ft.), fringed by beaches and tropical rainforest.
Ko Wua Talab (Sleeping Cow Island) is the largest of the 40 and is home to the National Park Headquarters, where there are some very basic four- to eight-person accommodations (book through the park headquarters at tel. 07728-6025, or online at www.dnp.go.th), but most just visit for the day. The island has freshwater springs and a park-run restaurant. Note: Pack a pair of strong walking shoes for the steep hills; flip-flops won't be able to take the gradient.
Ko Mae Ko (Mother Island) is known for both its beach and Talay Noi, an inland saltwater lake with a hidden outlet to the sea (the inspiration behind the film The Beach). Known to the Thais as Ang Thong, or "Golden Bowl," this turquoise-green lagoon gave its name to the entire archipelago. Endless companies offer day trips by speedboat. Some include snorkeling and kayaking trips with a range of prices; Blue Stars (tel. 07741-3231; www.bluestars.info), in Chaweng, is a good operator to try.