The Caño Negro Wildlife Refuge and the Rio Frio are biological humid areas considered to be one of the richest in biological diversity in the country. There is a great variety of resident and migratory birds plus three different species of monkeys, also iguanas, sloth, turtles and caimans.
There are no public facilities at this park. Due to the wetlands, this area can only be explored by boat. Fishing is allowed during certain parts of the rainy season.