Guanica State Forest (Bosque Estatal de Guánica) is also the name of a small dry forest reserve east and west of the town, the largest remaining tract of tropical dry coastal forest in the world, and designated an international Biosphere Reserve in 1981. The park comprising much of the dry forest is known as el bosque seco de Guánica.
San Juan National Historic Site includes forts San Cristóbal, San Felipe del Morro, and San Juan de la Cruz, also called El Cañuelo, plus bastions, powder houses, and three fourths of the city wall. All these defensive fortifications surround the old, colonial portion of San Juan, Puerto Rico and are among the oldest and best preserved Spanish fortifications of the Americas. The park consists of multiple sites. Castillo San Cristobal is one of the largest Spanish fortresses in the new world. The center offers English and Spanish versions of an introductory film to the Historic Site, exhibits, and a bookshop. The park also includes most of the historic city walls, and tiny Fortín San Juan de la Cruz (or el Cañuelo) located across the harbor on Isla de Cabras.
San Sebastian Annual Carnival, annually in January, it is one of the most popular festivals in the Caribbean, full of activities, parades, food and live music.
Mona Island, off of the west coast of PR, half way to the Dominican Republic, this island is a secluded island only inhabited by wildlife. There is no rarer wilderness adventure in the Caribbean than a trip to Isla Mona, Puerto Ricos ‘Jurassic Park,  50 miles to the west of the main island in the Pasaje de la Mona. And although few Puerto Ricans or travelers actually ever visit Mona, this circular island looms large in many peoples imagination. You suddenly begin taking the long view of our planets history when you see the violet cliffs of the tabletop island rising like a mirage above the deep blue waves, or a collection of giant iguanas scrambling onto a trail to sniff your scent. Mona is so full of history, dramatic geological formations and wildlife that it can overwhelm your senses and pique your curiosity in ways you cannot even imagine.
Rio Camuy Caverns in the north/northwest; a walking tour of the main cave, Cueva Clara, including a view of the "3rd largest underground river in the world" and an enormous sinkhole.
Vieques. With a name stamped in infamy, Vieques was where Puerto Ricos most prickly political saga was played out in the public eye. Over the centuries, residents and visitors who share affection for this place have come to call Vieques Isla Nena, a term of endearment meaning Little Girl Island.
Ponce. To understand the essence of Ponce itself, start at the city center, lined with shops, banks and surprisingly affordable hotels. The city has a more easygoing spirit than other major cities on the island, with businesses that open late and close early, couples who stroll circles around the citys fountains, and breezy evenings 2 miles south at the shore line.