On the Pacific side of Costa Rica, lush rain forest enfolds Playa Manuel Antonio, a crescent-shaped stretch of white sand just outside the sportfishing town of Quepos. This popular beach and national park hits all the right notes for a tropical beach fantasy, from the capuchin monkeys that try to filch your possessions to the casado (a traditional mix of rice and beans) with mahimahi for $12 at oceanfront Marlin's Restaurant (506/2777-1134).
The best snorkeling opportunities are in the waters above Costa Rica's most extensive coral reef, which lies off the southeastern coast near the Panamanian border. One fishing community here, palm-fringed Playa Manzanillo, offers a particularly irresistible laid-back vibe, with fishing boats drawn up on the sand and reggae music drifting from funky beachside bars. Activities in the area stretch beyond snorkeling to include boogie boarding and mountain biking.
The Nicoya Peninsula in northwestern Costa Rica is the ultimate diving destination. Pinch your nose and plunge into a huge concentration of eagle rays, giant mantas, marine turtles, and whale sharks. Among the many fine dive sites here, the standout is Playa Ocotal, a silvery beach surrounded by craggy headlands (Ocotal Beach Resort diving safaris, ).
Wildlife abounds along the trails that lace many of the national parks and reserves in Costa Rica. For a misty and mystical jungle trek through a cloud forest, unsung Santa Elena Cloud Forest Reserve (), outside Santa Elena, fulfills everything an ecotourism enthusiast could desire. It crawls with quetzals, kinkajous, and howler monkeys. Unlike neighboring Monteverde Cloud Forest—more famous because it came first and helped put Costa Rica on the ecotourism map—Santa Elena has a handy observation tower. Keep an eye out for endangered spider monkeys, named for their unusually long gangly limbs and prehensile tails.
Tucked away in Costa Rica's far southwest, near the surfing community of Pavones, the mountainside fruit farm Tiskita Jungle Lodge () serves as a fantastic base for ecotourism (rates from $250, closed September and October). It stands in a rainforest reserve teeming with creatures like scarlet macaws, toucans, and agoutis, huge rodents the size of housecats. Tiskita's resident guide Luis Vargas enthralls visitors with explanations of the area's ecosystems on his day and night walks to local deep-forest waterfalls. If you opt instead for budget digs—like nearby Rancho Burica's thatched cabanas (, from $8)—you can still take advantage of Vargas's services by contacting the lodge.
For a true challenge, attack the Sendero El Termometro trail in south central Costa Rica. The ascent takes two days. Depart from the nearby town of San Gerardo de Rivas, rise through cloud forest and alpine savannas, and reach the summit of the country's highest peak, the 12,530-foot Cerro Chirripó. Before your trek, contact the Parque Nacional Chirripó ranger station in San Gerardo de Rivas and reserve beds at the cozy mountain lodge Centro Ambientalista El Páramo, the sole lodging, a short distance below the summit; no camping is permitted (506/2742-5083). Guides can be arranged at the ranger station.
Monkeys howl and toucans screech as you career down the Reventazón River, experiencing white-water rafting at its rollicking best. The rapids are roughest in the fall, when the water level is highest. The top outfitter is Ríos Tropicales () in San José, which has more offerings than its competitors and a great reputation for trips down the Reventazón and Pacuare rivers; it even has its own isolated lodge on the Pacuare as a base for multiday trips.
Get your heart pounding by taking a zip-line ride through the forest canopy. Among the dozens of options, the best is Sky Trek () at Arenal, where you'll whizz along 1.7 miles of cables slung between towering trees. To get to the zip-line, you'll ride the Sky Tram (included in the Sky Trek experience), which offers views of Arenal volcano, a dramatic sight when it's venting. Children as young as 8 can enjoy the experience.
Hop on an ATV for a four-wheel joyride. Paraíso Adventure (), at the Pacific beach resort of Jacó, about two hours southwest of San José, gets high marks for its Jungle & Safari Tour (from $85 per person for a half day). The company makes it easy for you to add to the thrill of an ATV excursion by showing you where you can splash through mud, roar up mountain slopes, and stop to swim under a chilly waterfall.
7 insider tips
1. Costa Rican hotels are notorious for not honoring reservations. If you book by phone or fax, be sure to get a written confirmation. Prior to arrival, reconfirm.
2. Staying at a mid-priced hotel? Bring your own shampoo, washcloth, and even sink plug. Quite a few hotels lack these.
3. Planning to view birds or other wildlife? Pack khaki clothing, so you can blend in with the rain forest. And once you're on the trail, be patient. If a troop of monkeys passes overhead, wait quietly for a few minutes. Ground-dwelling animals may emerge afterward to feed on fruits dropped by the monkeys.
4. Even drivers of official taxicabs—red with a yellow sign with the plate number on each front door—can be reluctant to use the meter (la maria). Insist that yours does so, or expect to pay more than the meter rate. Alternately, check with your hotel concierge for the appropriate fare to your destination, and settle on a rate with the driver before you set off.
5. Parking a rental car at a surfers' beach? Don't leave anything in your vehicle. Break-ins have reached epidemic proportions, especially along the Nicoya Peninsula.
6. Riptides—narrow, fast-moving ocean currents that flow away from shore—claim many swimmers' lives each year. Ask locals about sea conditions before you dive in. Most riptides (also known as rip currents) are not identifiable to everyday beachgoers. If you get caught in one, swim parallel to shore to escape.
7. Rainforest Publications' waterproof, pocket-size, foldout field guides are handy for identifying wildlife species. They're widely available in gift shops in Costa Rica and from the company directly ().
Costa Rica's dry season (November through April) has the best weather, but it is also the high season, when rates increase. The May through October wet season is cheaper and less crowded.
• Pint of locally brewed Imperial beer: $2 (1,115 colones)
• Plate of gallo pinto, rice and beans with traditional salsa lizano: $3.25 (1,800 colones)
• Hand-painted ox cart souvenir: $7 (3,899 colones)
• Taxi ride () from the airport to downtown San José: $16-$20 (8,912-11,142 colones)
• Average rate for a two-star hotel in San José: $50-$60 (27,855-33,426 colones)