Surf by Moonlight
The breaks at Diamond Head, an extinct volcanic crater on the southern end of the island, are among the best on Oahu—and at night, basking in the light of a full moon, surfers can experience an even more intense thrill. For liability reasons, almost no resorts offer this as a guided excursion, but those brave enough to try can shack up at the Modern Honolulu, a stylish boutique hotel on Waikiki Beach that's 20 minutes from Diamond Head.
Free, but you need a surfboard and a glow stick to hang around your neck (rooms start at $319); the next full moon is on August 10, and it's best to time your trip to coincide with one.
Stargaze in the Desert
San Pedro de Atacama, Chile
At an elevation of 8,000 feet, the Atacama Desert has the clearest skies in the world, not to mention the luxury eco-resort Alto Atacama, which sits in the north of the 40,000-square-mile arid expanse, a three-hour trip from Santiago. Its outdoor observatory features a 16-inch telescope, perfect for an amateur stargazer's intro to the night skies. There's much to see: The desert is close enough to the equator to provide viewing access to 73 percent of the northern sky.
On-site activities—guided stargazing begins at 8 P.M.—are included in the hotel rate, which starts at $560; the sky is clearest in June, July, and August (the moon's glow compromises clarity, so plan around the four to five days before and after a new moon).
Reggae aficionados may want to skip the white-sand beaches and hit the Blue Mountains, where Strawberry Hill Hotel, a resort of 12 Georgian-style cottages built by Island Records founder (and former Bob Marley manager) Chris Blackwell, doubles as a tony home base for hikers. Go on the chaperoned nine-mile trek up Jamaica's highest peak (7,400 feet): It starts at 2 A.M. in order to arrive at the top by 5:30, just in time for sunrise and a commanding view of Jamaica's rolling green hills.
$40 for up to five people (rooms start at $270); Jamaica's peak season is December through April.
Sleep Under the Stars
Little Makalolo Camp, a rustic lodge (think canvas wall partitions) that's a one-hour flight south of Victoria Falls, overlooks a busy watering hole for zebras, giraffes, and elephants. Guides start up their Jeeps around 5 P.M. (the animal kingdom awakens at night), and you're likely to spend the next three hours rolling up to lions, aardvarks, serval cats, and leopards. After the safari, around 10 P.M., guests can choose to forgo base camp and sleep under the stars on a roofless raised platform—a bungalow on stilts—15 minutes deeper into the bush and near a separate watering hole favored by hyenas.
Rates start at $752 per person; Zimbabwe's dry season is July through September, and the brown foliage is less obscuring; piquetravel.com.
Snorkel After Sundown
Anse des Pitons, St. Lucia
Guests at the Viceroy Sugar Beach can gear up—with snorkels, fins, and water-proof flashlights—to explore the National Marine Reserve reef right from the hotel's beachfront on Anse des Pitons (Pitons Bay). It's teeming with nocturnal sea creatures like octopus, squid, trumpet fish, and, occasionally, sea horses; purple marine worms can grow to 15 feet long, locals allege. And in the summer months, you can swim among glowing plankton.
$27 for an hour, equipment and guide included (rooms start at $385); 7 P.M. to 9 P.M. are optimal snorkeling hours, but tours run until about 11 with 24-hour notice.
Also on Details.com:
Details' Ultimate Travel Guide
An International Guide to Sporting Vacation Destinations
This Is Not Your Father's Bachelor Party: 10 International—Stripper-Free—Themed Destinations