This wildlife refuge is located close to Nicaraguan border and is formed mainly by wetlands, with Cano Negro Lake being one of the most important. During the dry season (December-March) the water level on most trips begins at Frio River, where you travel on a boat through a series of canals the surrounds the wildlife refuge. By birders, it is considered one of the best places for observing birds on the continent. Also, it is possible to experience a wide variety of wildlife such as caimans, monkeys, bats, and sloths.