Beyond its 272 miles of beaches, Puerto Rico enjoys a wealth of natural and scientific attractions. Puerto Rico is home to nature reserves, many of which fall under the auspices of The Conservation Trust of Puerto Rico, The Trust, established by the Puerto Rico and United States governments in 1970, protects and manages 20 natural and historic areas in the Commonwealth.
Most everyone who visits the eastern region of Puerto Rico (and since San Juan is here, many people do) also visits the 28,000-acre El Yunque Rainforest, a UNESCO World Biosphere Reserve and the only rainforest in the U.S. National Forest System. El Yunque means “Forest of Clouds” and is named after the Taíno spirit Yuquiyu. It is known for its biodiversity: it's home to 240 species of trees, 23 of which are found nowhere else in the world. Here, throngs of visitors swim in the waterfalls, hike, picnicking and camp (with permit). The El Portal Rainforest Center provides educational exhibits and a theater.
In Fajardo, Las Cabezas de San Juan is a 316-acre nature preserve that features mangroves, lagoons, cliffs, and cays. Situated on the northeastern tip of the island, Las Cabezas affords sweeping views of the Atlantic Ocean as well as El Faro, a 19th-century Spanish colonial lighthouse recently restored by the Conservation Trust.
Also in this region, the Piñones Forest features a boardwalk that sets a course for visitors to follow among the mangroves and pines.
In Puerto Rico's northern region, the Reserva Natural Laguna Tortuguero is a lagoon reserve inhabited by several endangered species and tropical plants, of which private tours are available by appointment only. Visitors to this region will also find the 375-acre Bosque Estatal de Cambalache forest and the rarely visited Guajataca Forest as well as the Parque de las Cavernas del Río Camuy, a network of caves and sinkholes set within a 268-acre national park and one of the world's longest underground river systems. The Arecibo Radio Telescope, the largest telescope in the world, sits in Arecibo. Visitors can visit the observation deck and learn more through an onsite exhibit and film.
The western region of Puerto Rico is widely known for its surfing and beaches (most notably Boquerón and Rincón), but it also features the Guanica State Forest, a dry woodland that was designated a UNESCO World Biosphere Reserve, features hiking trails, swimming, more than 700 types of plants and 135 varieties of birds.
In Utuado, in the central region, the 7,000-acre Rio Abajo Forest features extensive hiking and mountain-climbing options and includes the highest peak in the Cordillera Central Mountain Range. Near Barranquitas, visitors will find Puerto Rico's only volcanic rift, along with its two rivers that run at a depth of nearly 650 feet, at the San Cristobal Canyon.
In the southern village of La Parguera, visitors are drawn to the Bahia Fosforescente, one of Puerto Rico's bioluminescent bays. The water in these bays glows a blue-green light created by non-toxic single-cell plankton. It's believed that the light is a natural defense system that allows the plankton to distract would-be predators by illuminating more appetizing prey. Visitors here often kayak or swim in the water and admire the glowing trails their movements leave behind. This region is also home to many of Puerto Rico's best dive sites, including Black Wall, named for the rare black coral and Hai Lite, which is rich with jewfish, trumpetfish, and giant tube sponges. Just north of Ponce, the 7,000-acre Toro Negro Forest reserve features a 3,650-foot peak (Pico Doña Juana), natural hot springs, and the 200-foot Doña Juana Falls.
Puerto Rico's smaller islands also contain extensive natural reserves. In Culebra, the Culebra Natural Wildlife Refuge, also known as Ultima Virgen, or Last Virgin, encompasses three offshore islands as well as tracts of land on Culebra Island itself. The 1480 acres are home to more than 120 marine bird-nesting colonies. Culebra is also home to Flamenco Beach, famous for its soft white sands. Puerto Rico's smaller islands, Mona and Monita, are often referred to as the Galapagos of the Caribbean. Unspoiled by inhabitants or lodging facilities, these islands are good options for hiking and diving and are home to several species of endangered marine life. Finally, the island of Vieques features another, and possibly more famous, bioluminescent bay, Mosquito Bay, where visitors swimming or kayaking in the water wonder at its unearthly glow.