Ha Long Bay has grown in popularity over the years and while you have to do your research in selecting a tour boat, it's still a beautiful place to explore, and a classic introduction to Vietnam's dramatic limestone formations.

A UNESCO World Heritage Site in Sarawak, Malaysia, Gunung Mulu National Park is famous for its rock pinnacles and caves.

A two-hour train ride from Hanoi, Trang An Scenic Complex is the shining star of Ninh Binh, flush with waterways, limestone cliffs, hiking and biking trails and caves that can be explored by rowboat.

Angkor Wat is Southeast Asia's most well-known temple complex and draws more than two million visitors per year. Though often crowded at its main sites, the majority of the complex is undervisited. Rent a bike and explore.

An old-world complex comprised of more than 2,000 Buddhist monuments, Bagan is Myanmar's answer to Angkor Wat. It was at its height from the 9th to 13th centuries and had an estimated 10,000 temples at that time.

The gateway to many outdoor attractions, including the Kuang Si waterfall, Luang Prabang is the launching point for nature seekers in Laos. The ancient capital and its many temples sit at the scenic juntion of the Mekong and Nam Khan rivers.

Ulu Temburong was the first national park established in Brunei (1991). It can be reached only by boat, requiring a trip up the Temburong River in an Iban longboat, the traditional form of transportation.

Snorkeling, scuba diving, hikes and beaches. Throw in the infamous Komodo Dragons and one could make a case that Komodo National Park is one-stop shopping in Indonesia.

Named for their color during the dry season, the Chocolate Hills are one of Southeast Asia's most unique topographies, located on the island of Bohol.

Palawan, although often referred to as a singular place, is an archipelago of islands in the Philippines. A myriad of national parks, marine parks and sanctuaries pave the way for ocean-based adventure in this pristine paradise.

Krabi's days of living in the shadow of Phuket are over. White-sand beaches, backpacker bars, limestone cliffs and lush terrain has fueled its growth in recent years.

Lake Toba occupies the remains of an old caldera, more than 62 miles long and nearly 20 miles wide. Its shores are inhabited by local Batak tribes, known for their curved-roof houses.

Once a backpackers' party destination, Vang Vieng has reinvented itself as an outdoor paradise. The goods were there all along, of course, but the last few years have seen an increase in eco-friendly tour companies offering adventures in the region.

Inle Lake offers a scenic retreat in Central Myanmar, headlined by its floating villages and surrounding wineries.

Laos is landlocked, but that doesn't mean you can't get an island experience. Si Phan Don refers to the group of islands in the Mekong River, which are accessible during the dry season for swimming and biking.

Tiny Sipadan Island, hidden off the northeast coast of Borneo, is considered one of the top diving destinations in the world. It's a long way to get there any way you slice it, meaning only the most serious divers find their way.

Phong Nha - Ke Bang National Park is on the World Heritage List for its cave system and underground rivers, as well as its trekking and biking. Go for the former, stay for the latter.

Mt. Kinabalu is the highest mountain in Malaysia. Located on Borneo, it is known for its trekking routes.

The volcanic history at Bromo is bustling, with five volcanoes grouped together in an old caldera (four active). The Park also contains the highest peak of Java, Mount Semeru.

The northern highlands of Vietnam surrounding the hub of Sapa are primed for treks through rice terraces and local villages.

Taman is considered one of the oldest rainforests in the world. River trips are popular, as are treks to the top of Mt. Tahan.

Khao Sok National Park in Southern Thailand is home to big game, including wild elephants and Malayan sun bears. Day and overnight wildlife tours are available via foot, boat or kayak.

Khao Yai National Park is Northern Thailands version of Khao Sok, primed with dense forests that are home to elephants and bears.

Pulau Ubin is home to one of Singapore's last kampongs, or villages, and it's a rare taste of rustic, rural life in Southeast Asia's most westernized country. Additionally, the island has opportunities for hiking and mountain biking.

Looking for a scenic beach in Singapore? Try Lazarus Island, a short ferry ride from the Marina South Pier. While it's catching on in recent years, the still-undeveloped island remains a nice day-trip getaway.