With nearly 800 miles of coastline stretching along two oceans, it's no surprise that more than a million surfers and sun worship-pers flock to Costa Rica to enjoy its fabulous beaches each year. But in addition to breathtaking white sands and emerald-azure seas, many of Costa Rica's "riches" lie inland.

Costa Rica has a land mass barely the size of West Virginia, yet it contains 5 percent of the world's animal and plant species. Three million years ago, when a volcanic archipelago stretching between North and South America merged and created Costa Rica, it connected two biologically and evolutionarily different groups of animal and plant species. And thanks to elevations that range from sea level to 12,530 feet, and climates that vary from the hot and dry savannas of Guanacaste to the cool cloud forests of Monteverde, many of these species survived.

Today this bountiful isthmus contains 10,000 varieties of plants, 250 species of mammals, 225 kinds of reptiles, 175 types of amphibians, 900 species of birds and more than 300,000 different insects spread over 20,000 square miles. And given that Costa Rica is an international model for eco-tourism, there are endless ways to learn about and experience this country's riches.

But with 26 national parks to choose from, where do you go? It all depends what you're looking for.

Arenal Volcano National Park: This park has the most active volcano in Costa Rica and one of the country's better-known attractions. This 30,000-acre park, like much of Costa Rica, is home to a wide variety of fauna, including sloths; howler and white-faced monkeys; jaguars; coatis; and a large proportion Cost Rica's 900 species of birds. You'll also find numerous flowering trees, palms, bromeliads, fungi, orchids and ferns. To view these wonders, the park has miles of hiking, horseback and mountain-biking trails around the volcano and lake. When you're done exploring the volcano, you can wash off the trail dust in the crystal-clean natural pool at the base of the 70-meter-high La Fortuna Waterfall, take a dip in 105-degree mineral hot springs or enjoy a safari float down the Penas Blancas River.

Monteverde Cloud Forest Reserve: Close to Arenal is the famed Monteverde Cloud Forest, named by National Geographic and Newsweek magazines as one of the world's top destinations for natural beauty. The reserve has more than 26,000 acres of tropical rain forest, six ecological zones (90 percent of which are virgin forest) and an incredible number of plant and animal species, even by Costa Rican standards. There are more varieties of orchids here than can be found at any other location in the world. If you're looking for one-stop shopping for Costa Rica's trademark biodiversity and beauty, this is it.

Manuel Antonio National Park: If you want to mix your wildlife excursions with some beach time, another easily accessible destination is this park. Located 100 miles south of San Jose on the Pacific coast, Manuel Antonio is known for its blazing white sand, rich tidal pools, crystal blue waters and colorful coral reefs ideal for snorkeling. (Dolphins and migrating whales are a common sight.) In addition there are 1,700 acres of primary and secondary forests where cedars, bully, black locust and silk cotton trees provide shelter to squirrels, howler and capuchin monkeys, three- and two-toed sloths, white-nosed coatis, black spiny-tailed and green iguana, basilisk lizards and 180 varieties of birds.

Corcovado National Park: For the more adventurous and those who want to escape the crowds, Corcovado National Park on the Osa peninsula along the southern Pacific Coast has the largest old-growth forest on the American continents' Pacific coast and one of the largest areas of low-elevation tropical rain forests in the world. This is one of the few parks where you can see Costa Rica's big cats and tapirs as well as the endangered spider monkey. The park also has a large population of scarlet macaws, one of Costa Rica's most celebrated birds. Corcovado is not for the Hyatt-goer. Lodging is either dorm room or camping, and you have to pack your own food and water. The authorities require that you get a permit in advance, but you can pay at the ranger station in Puerto Jimenez.

Tortuguero National Park: On the northern Caribbean side of the island is Tortuguero National Park. This region is best known as a nesting spot for sea turtles. Most of the turtles in the park are green turtles, which nest from July to October. Leatherbacks, less common, nest from February to June. Hawksbills and loggerheads, also less common, nest in summer. Pregnant turtles are easily scared and if startled might return to the water and die without laying their eggs. The best way to view Tortuguero's other natural wonders is via kayak or guided boat along the park's many rivers and canals.

With so many national parks and a $2 billion-a-year ecotourism industry, Costa Rica is a nature lover's paradise. Just be careful not to love it too much. Wild animals, by definition, generally aren't comfortable around humans, so give them plenty of space (binoculars or a camera zoom are highly recommended). And this advice is not just to protect the animals: Trust us, you don't want to have a 6-foot-long jaguar chasing you down the trail.

If you go

Getting there: Daily flights from New York, Washington, Miami, Atlanta, Houston, Dallas and Los Angeles.

Communication: Cellphone reception is good; Internet service is widespread; Internet cafes are common.

Credit cards: Most international credit cards are accepted throughout the country. ATMs are easy to find and offer local currency and U.S. dollars.

Where to stay

Manuel Antonio: economy, Hotel Mono Azul (hotelmonoazul.com); high-end, Hotel Si Como No (sicomono.com).

Arenal Volcano: economy, Mayo Lodge (mayollodge.com); high-end, Hotel Cabanitas (hotelcabanitas.com).

Monteverde Cloud Forest: economy, La Colina Lodge (lacolinalodge.com, camping available); high-end, Hidden Canopy Tree Houses (hiddencanopy.com).

Corcovado: camping and dorms, permits/reservations, (corcovadoguide.com/permitting.htm).

Tortuguero: economy, Casa Marabella (casamarbella.tripod.com), high-end, Manatus Hotel (manatuscostarica.com).

ctc-travel@tribune.com