Singapore is known as a bustling metropolis that also happens to be one of the cleanest and safest cities of its size in the world. (Just make sure you heed the local laws—something like spitting in the street might merely be considered rude in your hometown, but here, it carries a severe penalty.) You'll find historic sites like the Thian Hock Keng temple, superlative shopping (including gargantuan malls) and numerous beaches.

Johor Bahru is the second-largest city in Malaysia and, with the opening of two major amusement parks in 2012, it is poised to become a major tourist destination. TripAdvisor travellers also recommend visiting the Arulmigu Sri Rajakaliamman Glass Temple, a unique Hindu temple decorated with brilliant glass mosaics.

This charming city is a UNESCO world heritage site, with a rich trading history and multicultural heritage. Melaka is a rewarding town to explore and is about two hours from Kuala Lumpur.

The cultural hub of Malaysia, Kuala Lumpur is visually defined by the iconic Petronas Twin Towers, which, at 88 stories high, are the tallest twin buildings in the world and a vision of modern architecture. On the flip side, the Sri Mahamariamman is the oldest Hindu temple in Malaysia, its façade a colorful totem pole of iconography. Shopping at the Central Market is a joyful experience that involves haggling, handicrafts, and happiness.

Vietnam's bustling largest city sets the cultural and economic pace for the country. The former Saigon boasts charming French colonial architecture and wide boulevards, usually thronged and choked with traffic. Taxis are an option for seeing the sprawling city. The War Remnants Museum shows the Vietnam War through Vietnamese eyes. Don't miss the impressive Jade Emperor Pagoda. Go to the frenetic Ben Thanh Market for food, flowers or frogs. Tour through the Mekong Delta, past rice paddies and houseboats.

Famed throughout Asia for its heady mix of eastern cultures, Penang Island is Malaysia’s prime melting pot. Roadside vendors serve some of the world’s best street food; its national parks offer white-sand beaches and wildlife; and UNESCO-listed George Town is full of colorful heritage houses.

China’s third-largest city is the capital of Guangdong Province and a thriving commercial centre. Its location on the Pearl River and proximity to Hong Kong has made Guangzhou a strategic port for centuries. Glimpse old temples and gleaming steel towers on an architectural tour. Visit one of four Chimelong theme parks for thrills and chills. Once called Canton, Guangzhou is considered the home of traditional (read Cantonese) “Chinese food.” Foodies will find more restaurants per capita here than anywhere else in China.

Bangkok is full of exquisitely decorated Buddhist temples—as you go from one to the next you’ll be continually blown away by the craftsmanship and elabourate details. But if you’d rather seek enlightenment in a gourmet meal, or dance the night away, you’ll also enjoy Bangkok—the restaurant and nightclub scenes here are among the best in the world.

The charming Vietnamese capital has aged well, preserving the Old Quarter, monuments and colonial architecture, while making room for modern developments alongside. Hanoi may have shrugged off several former names, including Thang Long, or "ascending dragon", but it hasn't forgotten its past, as sites such as Ho Chi Minh's Mausoleum and Hoa Lo Prison attest. Lakes, parks, shady boulevards and more than 600 temples and pagodas add to the appeal of this city, which is easily explored by taxi.