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.
KO TAN & KO MAT SUM
Just a 15-minute boat ride from the shores of Ko Samui, Ko Tan, and Ko Mat Sum feel worlds away. The islands have pristine white-sand beaches, and the human traffic is minimal, so you’ll feel like the mayor of your own private island. Fishmongers slowly buzz by on rickety boats, and a few speedboats pop in and out during the day—but the rest of the time is blissful solitude. Schools of colorful fish live just off shores of Ko Tan so plan to bring a mask (or rent one in Samui from a number of dive and snorkel shops) or just enjoy the island views and swimming in the crystal-clear water. On Ko Tan, guests can enjoy a leisurely walk along an elevated wooden platform through the island’s mangrove forest. Ko Mat Sum is much smaller than Ko Tan but has a swell castaway vibe. A few enterprising locals rent beach chairs and sell bags of chips and ice-cold beers. If you think you’ll want to stay a full day, you might want to ask your hotel to prepare a picnic lunch, otherwise, there are a few beach huts that sell basic Thai dishes, like fried rice, coconut curries, and—if the fisherman have stopped by that day—grilled prawns or steamed seabass.To get to Ko Tan or Ko Mat Sum, hire a longtail boat from the Thong Krut Pier on the south coast of Ko Samui. Most drivers charge between 1,500B and 2,000B for a half-day trip (around 4 or 5 hours). Make sure you’ve agreed upon terms before getting on the boat. The driver will drop you near the shore and come back at the assigned time (but its smart to get his phone number). Ko Mat Sum is about a kilometer east of Ko Tan, so ask the boat to take you there. One more thing: Like many islands and places in Thailand, Ko Tan has several names. Ko Tan is the most common name, but some call it Ko Tean, and the island is listed as Tean Island on Google Maps.