Caño Negro Wildlife Refuge in the northern part of Costa Rica is a wetlands site that is home to manymigratory waterfowl during part of the year, centered on Lake Caño Negro which is fed by the Frío River during the rainy season. There are no public facilities at the refuge, and the area can be explored only by boat.

The forests, grasslands and marshes of the area provide shelter for various endangered species such as cougars, jaguars, tapirs and ocelots, peccary and several species of monkey (white-headed capuchin, mantled howler and spider monkey), as well as many others. In the dry season area is reduced to little lagoons, channels and beaches which gives home to thousands of migratory birds of many species such as storks, spoonbills, ibis, anhingas, ducks and cormorants.