City-states are rare in the present day—and none are quite like Singapore. In the 20th century, the Southeast Asian nation hurtled itself into the modern world, and it continues to expand its state-of-the-art transportation system and build its edgy skyline. Yet Singapore’s urban plan wisely maintained its intimate neighborhoods, many with streets lined with colorful shophouses (a type of building unique to parts of Asia, with businesses located on their ground floors and residences above). Add the city’s mix of ethnic groups—mainly Malays, Chinese and Indians—and you get a vibrant cultural scene that attracts a cosmopolitan, international community. Singapore’s food scene—which is arguably the world’s most dynamic and runs the gamut from beloved street hawkers to Michelin-starred venues—would merit a trip alone, as would its never-ending shopping options. But the city is also packed with world-class museums, many designed by celebrated architects, and it hosts many major international events, such as the Formula One Grand Prix. Yet only about half of the 720-square-kilometer (278-square-mile) island is developed, which leaves plenty of room for parks and open spaces such as the Bukit Timah Nature Reserve, where an old-growth forest still thrives.

Koh Samui can feel like a screensaver landscape. As if designed by Mother Nature for posters, calendars and daydreams, it’s Thailand’s most famous island for a number of reasons. The beach-fringed coast is edged with vivid, blue water that’s a surf-and-sand playground for snorkeling, scuba diving, kayaking, building sandcastles and simply lounging. Along with busy food stalls and restaurants where you can find a whole world of cuisine made with local produce and fresh seafood as well as authentic Thai dishes, the lively streets are lined with bars, boutiques, markets and spas. By contrast, the island’s interior can provide moments of reflection and replenishing solitude. Enter the dense, hilly jungles for hikes to ancient temples and pristine waterfalls and quaint villages where you can experience true Thai hospitality. With dreamy landscapes and island adventures from boat excursions to nature treks, you’ll soon be enchanted by Koh Samui.

Thailand, known as Siam until 1932, is the only country in Southeast Asia (and one of the few in the world) never to have been colonized by a European power. Its capital, Bangkok, reflects the country’s unique status. It has embraced modernity on its own terms as the seat of a beloved monarchy that dates back to the 13th century. In this city, Buddhist temples and gilded palaces coexist with the bustle of one of Asia’s major metropolises. The contrast between the golden glow of sunrise along the Chao Phraya River, which runs through the municipality, and the neon lights of downtown can feel intoxicating. There are few places in the world where you can spend the morning visiting a centuries-old stupa, have lunch at one of the world’s top Michelin-starred restaurants and then shop for exquisite silk garments. And wherever you explore, you’ll be struck by the warm welcome you receive. “The Land of Smiles” may be a cliché and a tourism-marketing slogan, but it’s also a fitting nickname for Thailand. Many of the country’s most important historic areas can be found not far from Bangkok. Ayutthaya, the former Thai capital, is a UNESCO World Heritage Site with impressive Buddhist ruins. The 16th-century town of Chachoengsao is known for its many temples, including Wat Saman Rattanaram with its 22-meter-long (72-foot-long) statue of the Hindu god Ganesha. In Pattaya, on the coast, the Pattaya Elephant Village is a sanctuary for Asian elephants. Whether you travel by boat, bus or tuk-tuk (a three-wheeled motorized taxi) to explore Bangkok’s temples, palaces and markets, be prepared to fall in love with this city that somehow manages to be both chaotic and captivating at the same time.

Thailand, known as Siam until 1932, is the only country in Southeast Asia (and one of the few in the world) never to have been colonized by a European power. Its capital, Bangkok, reflects the country’s unique status. It has embraced modernity on its own terms as the seat of a beloved monarchy that dates back to the 13th century. In this city, Buddhist temples and gilded palaces coexist with the bustle of one of Asia’s major metropolises. The contrast between the golden glow of sunrise along the Chao Phraya River, which runs through the municipality, and the neon lights of downtown can feel intoxicating. There are few places in the world where you can spend the morning visiting a centuries-old stupa, have lunch at one of the world’s top Michelin-starred restaurants and then shop for exquisite silk garments. And wherever you explore, you’ll be struck by the warm welcome you receive. “The Land of Smiles” may be a cliché and a tourism-marketing slogan, but it’s also a fitting nickname for Thailand. Many of the country’s most important historic areas can be found not far from Bangkok. Ayutthaya, the former Thai capital, is a UNESCO World Heritage Site with impressive Buddhist ruins. The 16th-century town of Chachoengsao is known for its many temples, including Wat Saman Rattanaram with its 22-meter-long (72-foot-long) statue of the Hindu god Ganesha. In Pattaya, on the coast, the Pattaya Elephant Village is a sanctuary for Asian elephants. Whether you travel by boat, bus or tuk-tuk (a three-wheeled motorized taxi) to explore Bangkok’s temples, palaces and markets, be prepared to fall in love with this city that somehow manages to be both chaotic and captivating at the same time.

Known for its white sand beaches, warm Gulf of Thailand waters, and laid back atmosphere, Sihanoukville is a premiere beach lovers’ destination. Built in the late 1950s, the town is much newer and more cosmopolitan than most Cambodian provincial cities. Spend the day exploring miles of unspoiled beaches or chose one and swim, snorkel or simply relax under a beach umbrella. Sample shore excursions: Sihanoukville & Environs; Swimming at Sokha Beach Resort.

Whether you are on a wide boulevard admiring the French Colonial architectural influence, or in a bustling market haggling with a street vendor, you cannot escape the culture and history of this bustling city. Ho Chi Minh City is home to many colorful pagodas, cathedrals and palaces-including one of the city’s oldest, Giac Lam Pagoda, dating from 1744. Sample shore excursions: Cambodia & Angkor Overland Adventure or Highlights of Ho Chi Minh City.

White sand beaches, turquoise waters, beachfront cafés. Nha Trang’s days as an underappreciated treasure are over. Still very much intact since the 7th century are the venerated towers of the Cham Ponagar Temple complex. Sample shore excursions: Nha Trang City Tour; Nha Trang Countryside.

Located halfway between Hanoi and Ho Chi Minh City, the port city of Da Nang has a small-town charm despite its lack of big-ticket attractions. It is home to a stunning 30-kilometer (18-mile) coastline that is popular for water sports such as waterskiing, paddleboarding and surfing. It’s also known for its great street food—and an extremely quirky bridge that you can’t miss. The place was previously occupied by both the French and the Americans (this was the first place U.S. Marines landed in March 1965), and vestiges of both can be seen in the city, from the remnants of the vast U.S. air base and hospital to the city’s wide boulevards and old villas. Da Nang is a great launchpad for day trips, whether to the picturesque city of Hoi An to the south, the old imperial capital of Hue to the north, or the majestic Marble Mountains to the southwest. The UNESCO-protected Champa temple complex, My Son, which lies 69 kilometers (43 miles) southeast, is definitely worth the trip—but for those who don’t want to leave the urban environs, many of the ruins have ended up at Da Nang’s excellent Museum of Cham Sculpture, where you can learn all about the history and architecture of this fascinating culture.

Like a combination of Thailand’s famous limestone islanded Phang Nga Bay and old Hong Kong’s harbor with its dragon-sailed junks, Vietnam’s Halong Bay is fast making its way to the top of everyone’s Asian must-see travel list. The bay and its almost two thousand islands were declared a UNESCO World Heritage Site in 1994 giving an official stamp of recognition to this natural wonder that has captivated painters and poets for centuries. Halong City has several markets and restaurants worth visiting, and is also a convenient base before setting out for places like Cat Ba Island and some of the smaller islets with their underground caves and biodiverse wildlife. As you sail the bay or look at it from the mainland, you may feel like you’ve stepped into a postcard or a painting from the classic era of Vietnamese art. Some travelers come here for active days filled with kayaking, caving and islet-hopping but you can also sit back and simply sail through this stunning bay or take a day trip to fishing villages with their colorful markets. If you are up for venturing farther afield, it’s a three-hour trip (each way) to Hanoi but worth the effort if you have yet to visit the city.

Can any city in the world top Hong Kong’s phenomenal energy? Judge for yourself as you ride the tram to the top of Victoria Peak, join the surge into countless markets and watch the hardworking world of Aberdeen’s fishing junks. Sample shore excursions: Morning Tai Chi & Cooking Tour; Hong Kong Island City Sightseeing; Explore Lantau Island & Monastery.