Tortuguero:

This park has the largest protected tract of tropical rainforest in the entire Central American Caribbean area.
A unique attraction here is the network of canals connecting the Port of Moín with Barra del Colorado, providing the sole means of transportation. Tourists and locals alike use these meandering rivers, canals and lagoons for traveling through Tortuguero Park, winding their way through dense, lush greenery and keeping an
eye out for animals such as land turtles, manatee or sea cows, crocodiles, myriad crustaceans and some 85 species of fresh water fish, including gaspar fish.
The area also abounds in mammals such as tapirs, jaguars, ocelots, peccaries, monkeys, sloths and the fishing bat, one of the largest in Costa Rica. There are also numerous birds, such as green macaws (an endangered species), great curassows, turkey vultures, toucans and common black-hawks.
Barra del colorado national wildlife refuge:
Stretching along 50 km of coastline, this protected area boasts 92,000 hectares of canals,

lagoons, rivers, river islands, forests, swamps, yolillal marshes and hills (ancient volcanic cones). A variety of hiking trails crisscross the refuge, which also offers great sport fishing - though visitors are forewarned they’ll need to get a fishing license at the park ranger station.
As a very hot tropical rainforest, the refuge provides a home to a wide range of animal species, such as manatee (sea cows), caimans, crocodiles, gaspar fish and numerous schools of tarpon; mammals such as tapirs, jaguars, pumas, howler and white-faced capuchin monkeys, ocelots, jaguarundis, and three-toed sloths; and birds such as ospreys, keel-billed toucans, olivaceous cormorants, blue herons, tricolored herons, white hawks, great tinamous, great curassows, and red-lored parrots.
The scenery is unique, with a network of canals mixed with beach ecosystems and marine wildlife, and for those who enjoy a good hike, there’s a 45-minute trail up to Cerro Tortuguero.