Stretching from the fishing village of Puerto Morelos to the biosphere reserve of Sian Ka'an, the Mayan Riviera offers an unforgettable Caribbean coastline experience. Divers and snorkelers will be dazzled by the wrecks of Xcaret and the Puerto Morelos reef. Use a zip line to descend into the sacred subterranean caverns of LabnaHa Eco Park, where you can snorkel an underground river under a canopy of stalactites. The nearby Tulum Monkey Sanctuary will put you in a playful mood.

Puerto Aventuras mingles tropical beauty with the riches of the sea. Beaches are fantastic, with powdery, white sand, and there's excellent fishing as well. For a fun day, explore the eco-archaeological park Xcaret, or snorkel at Xel-ha, a natural inlet water park. The Mayan ruins at Tulum, only 25 minutes away, are another must-see.

It’s not just for spring-breakers. Cancun, with its golden beaches and perfect climate, is the premiere coastal destination in Mexico. And while there is certainly a 365-day party available for college students, resorts cater well to families and to those seeking solitude. This Yucatan paradise is also the gateway to the ruins of Tulum and Chichén Itzá.

Akumal means "Place of the Turtle" in the Mayan language, and if you snorkel here, you just might see one swimming alongside you. (Don’t touch it, though. That’s prohibited by law.) You’ll definitely see coral and beautiful fish in the clear, sparkling waters. This tourist-friendly little town is about an hour south of Cancun—but it seems light-years away.

Just north of Cancun, this seaside resort community is a far cry from the spring-break crowd. Bordered on one side by the Mexican Caribbean and the other by a wetlands wildlife preserve, the vibe in Playa Mujeres is one of laid-back luxury in a natural, untouched landscape. Unlike many other such tranquil places, Playa Mujeres is not a pain to get to. It's an easy ride from Cancun airport.

Once a sleepy fishing village, Placencia has emerged as an increasingly popular eco-destination on the Caribbean. For those who enjoy outdoor adventure, the Stann Creek region offers a host of activities: hiking through mountainous rain forests, kayaking, deep sea fishing, diving and exploring Mayan ruins. The peninsula boasts 16 miles of tranquil beaches, with a lagoon to the west and the Caribbean to the east and lots of peace and quiet in the middle. Tour guides and dive centers offer a variety of excursions, with boat rides to the outer cayes an ongoing favorite. Also popular are guided land tours to Mayan Ruins or trekking the jungle trails of Cockscomb Basin Wildlife Sanctuary, where the first Jaguar Reserve in the world was established.

Is there any possible way Las Vegas could not be on our "best nightlife" list? The only way we could possibly omit it is on a technicality—since you can do pretty much anything 24/7 in Vegas, it might be wrong to call it "nightlife."

If watching the sunrise from atop a 10,000-foot volcano, swimming under waterfalls, hiking through craters and luxuriating on white-, red- and even black-sand beaches sounds like paradise, then Maui awaits. Maui is the place to surf and windsurf. Or hop a catamaran to scuba and snorkel on Molokini Island, a crater emerging from the sea that hosts a wealth of marine life. Golf, fine dining, a winery, museums and sipping a mai tai on the beach round out the perfect tropical holiday.