There are 36 miles of trails in Bosque Estatal de Guánica [1]. From the main entrance off Carretera 334, follow the long narrow road to the information center, where you’ll find the trailheads and where you can obtain trail maps and tips from the helpful English-speaking rangers.
Among the most popular hikes are a 3-mile, 1.5-hour hike to the ruins of Fuerte Capron, once a lookout tower for the Spanish Armada and the site of an observation tower built by the Civilian Conservation Corps in the 1930s; a 40-minute loop trail ideal for bird-watching; a 35-minute hike to see the ancient Guayacán tree (300 or 1,000 years old, depending on the source); and a 2-hour hike to underground caves, which requires special permission from the information center and accompaniment by a guide.
If you’re planning to hike in the forest, be sure to wear sturdy shoes or hiking boots and bring a hat, insect repellent, sunscreen, and plenty of fresh drinking water.
Links:
[1] http://www.moon.com/destinations/puerto-rico/south-coast/guanica/bosque-estatal-de-guanica