This wildlife refuge takes its name from two of three rivers: Cuero and Salado, which meet at the coast in a large estuary, creating waterways, mangrove forests and lagoons along the way, and San Juan. A reserve since 1987, it protects varied and abundant wildlife; manatees are the most famous and most elusive, but there are also (among others) howler and white-faced monkeys, sloths, otters, iguanas, caimans and 196 species of birds.