This 9,900-acre United Nations Biosphere Reserve is a great place for hiking. An outstanding example of a tropical dry coastal forest, it has some 700 species of plants, from the prickly-pear cactus to the gumbo limbo tree, and offers superb bird-watching; its more than 100 species include the pearly-eyed thrasher, lizard cuckoo, and nightjar.
The popular Ballena Trail, which begins at the ranger station on Route 334, is an easy 1¼-mile (2-km) walk that follows a partially paved road past a mahogany plantation to a dry plain covered with stunted cactus. A sign reading "Guayacán centenario" leads you to an extraordinary guayacán tree with a six-foot-wide trunk. The moderately difficult, 3½-mile (5½-km) Fuerte Trail leads to an old fort built by the Spanish Armada. It was destroyed in the Spanish-American War in 1898, but you can see ruins of the old observatory tower.
In addition to using the main entrance on Route 334, you can enter on Route 333, which skirts the forest's southwestern quadrant, or try the less explored western section, off Route 325.
Rte. 334, Guánica, 00653, Puerto Rico