The ten best places to go in Costa Rica in no particular order
This is a subjective list—it's our opinions—so we can't possibly be wrong. If your opinion differs and you'd like to contribute let us know.

Corcovado National Park—One of the best places in the world to trek in the tropical rainforest, Corcovado has everything visitors to Costa Rica are looking for. The rise of small lodges means access is becoming easier for those who don't want to slog through the sucking mud with a pack on their back, but the interior will always pay dividends to those who travel under their own power.

Palo Verde National Park—is a relatively undiscovered jewel in the Costa Rican park system. The bird population, both native and migratory is spectacular. The trail system leaves something to be desired, but this certainly means fewer crowds, and there are a number of areas that can be explored by boat.

La Fortuna de Bagaces— Unlike its famous cousin to the east that it replaces on our list, there is essentially no tourist infrastructure in this sleepy hamlet between volcáns Miravalles and Rincón de la Vieja. There is easy access to beautiful swimming holes at the base of spectacular waterfalls, and incredible forests, the geysers and mud pots of Las Hornillas reminiscent of Yellowstone, abundant natural hotsprings, and a bull ring that still sees sabaneros meet their match in the corridas de toros.

Barra Honda Caverns—Not everyone is interested in spelunking, but those who are will appreciate the pristine condition of these caves. The small vertical entrances have protected these limestone caverns for millennia, first from discovery, then from entry by all but the most intrepid explorers.

Santa Rosa National Park—Daniel Janzen and his wife Winnie Hallwachs initiated a crusade over two decades ago that resulted in an incredible gift to the world. Santa Rosa National Park protects and provides a mechanism for restoration of perhaps the only significant tropical dry forest in the world that will survive our generation. The main campsites at the headquarters and on playa naranjo serve as jumping off points for extended explorations, La Casona is an important historical landmark, and witches rock marks the location of a surfer's paradise.

Puerto Viejo de Talamanca—Reggae provides the backbeat along the beaches and main street of this Caribbean village. Peppery fresh fish dishes, coconut curries, and fragrant spiced breads fill your plate. Sloths, monkeys, and birds abound in Cahuita National Park and Gandoca-Manzanillo National Wildlife Refuge up and down the coast respectively.

Wilson Botanical Gardens—The gardens at Las Cruces Biological station are only one of the rewards awaiting travelers who make the effort to visit the southern most reaches of Costa Rica.

Caño Negro wildlife refuge—Nature cruises through these wetlands are quite popular now, but don't worry there are thousands of acres to explore. A boat trip here or in Tortuguero, or Damas estuary is certainly the easiest and maybe the best way to see a lot of wildlife on your visit to Costa Rica.

Cerro Chirripó—Quite possibly our favorite place. The strenuous climb through seven distinct ecosystems allows you to experience most of Costa Rica's inland natural history in a single day. There are a growing number of visitors, but nearly all of them stick to the main route to the refugio under the peak. If you want a true Costa Rican wilderness experience there's still thousands of virgin acres here.

Manuel Antonio National Park—We hear complaints nearly every day that Manuel Antonio has been ruined by development and overcrowding. While it has changed significantly in the three decades since it was established, it's still one of the best places to visit in Costa Rica. Crowded is a relative term, Manuel Antonio is twice the size of New York City's central park, but visitors are limited to 600 at a time. The development allows for easy access for those who might not otherwise have the opportunity to explore one of the last patches of tropical wet forest.

Monteverde—This private reserve provides the easiest access to the cloud forests, and an infrastructure of guides and resources to help you make the most of your visit. Like Manuel Antonio, it has gained tremendously in popularity, but has much less chance of being loved to death. Monteverde is much larger, the cool, wet, windy weather means shorter visits, and as a private reserve it has better funding than most of the National Parks. Despite the growth in tourism in the surrounding community, a few hundred yards off the main loop (el triangulo) you're unlikely to see anyone else on the trail.