The largest city in China is also its most cosmopolitan, offering visitors a chance to experience the past, present, and future all at once. The Huangpu River splits Shanghai into two districts: Pudong and Puxi. The Pudong skyline looks like it was ripped from the Jetsons, with the bulbous Oriental Pearl TV and Radio Tower looking a bit like a two headed lollipop. On the Puxi side, you can walk the Bund riverside district to get a taste of old Shanghai.

The southern Thailand town of Krabi serves as base camp for exploring the province of the same name, a lush region of jungles, limestone cliffs and idyllic isles floating just offshore in the Andaman Sea. Buddhist shrines still used by local monks are tucked into the chambers of the town's top attraction, Tiger Cave. The riverside pier links travelers with ferries and longboats to the best scuba diving, rock climbing and white sand beaches on the coast.

Packed with all the amenities—and unsightly development—of a modern Thai harbor town, Ao Nang is a popular base camp for exploring Krabi’s karst islands. A long arc of sand is shared by long-tailed boats delivering day-trippers to resorts and rowdy beach bars.

Just 80 kilometers north of Phuket, Khao Lak was essentially erased by the 2004 tsunami. But the town, and the tourist industry it relies on, has rebounded. It remains quieter than other coastal destinations, offering secluded beaches, tranquil nights and family-oriented activities. You want full moon parties and besotted nights? You’re out of luck. But if you’re looking for unparalleled scuba diving in the Similan Islands, you’ve hit the jackpot.

Thailand’s largest island is an international magnet for beach lovers and serious divers, who enthusiastically submerge themselves in the Andaman Sea. Blue lagoons and salmon sunsets make for a dream-like atmosphere, and indeed, a vacation here can feel a bit surreal. Watersports are the most popular activities, though once you’ve had enough sun there’s still plenty to explore at the island’s aquariums, gardens, and Buddhist temples.

Though Mumbai can feel chaotic and crowded, there are peaceful moments to be found here. Nibble a paper cone of bhelpuri while you stroll the sands of Chowpatty Beach. Then, take a short walk to Mani Bhavan, where Mahatma Gandhi once lived, strategized, and was ultimately arrested. The markets are spirited places to bargain for spices or souvenirs. Take a guided tour of Dharavi – made famous by "Slumdog Millionaire" – for an eye-opening glimpse into what Mumbai life is like for nearly a million people.

Lovely, laid-back Melbourne has something for everyone: family fare, local and international art, haute boutiques, multicultural dining, Australian and Aboriginal history, spectator sports, and pulsing, swanky nightlife. Cruise on the free City Circle Tram loop to check out unique attractions like the Royal Botanical Gardens and the Healesville Sanctuary, which buzzes with local animal species.