• El Yunque (tel. 787/888-1880): Thirty minutes by road east of San Juan in the Luquillo Mountains and protected by the U.S. Forest Service, El Yunque is Puerto Rico's greatest natural attraction, the only tropical rainforest in the United States National Forest System. It sprawls across 28,000 acres (1,133 hectares) of the rugged Sierra de Luquillo mountain range, covering areas of Canóvanas, Las Piedras, Luquillo, Fajardo, Ceiba, Naguabo, and Río Grande. The area is named after the Indian spirit Yuquiye, which means "Forest of Clouds," who local Taínos thought protected the island from disaster in times of storms. Originally established in 1876 by the Spanish Crown, it's one of the oldest reserves in the region. There are some 240 species (26 endemic) of trees and plants found here and 50 bird species, including the rare Puerto Rican Parrot (scientific name: Amazona vitatta), which is one of the ten most endangered species of birds in the world. The foot-long parrot is bright green, with red forehead, blue primary wing feathers, and flesh-colored bill and feet. Some 100 billion gallons of rain fall here annually. Visitors and families can walk one of the dozens of trails that wind past waterfalls, dwarf vegetation, and miniature flowers, while the island's colorful parrots fly overhead. You can hear the song of Puerto Rico's coquí, a small tree frog, in many places.
  • Río Camuy Caves (tel. 787/898-3100): Some 2 1/2 hours west of San Juan, visitors board a tram to descend into this forest-filled sinkhole at the mouth of the Clara Cave. They walk the footpaths of a 170-foot-high (52m) cave to a deeper sinkhole. Once they're inside, a 45-minute tour helps everyone, including kids, learn to differentiate stalactites from stalagmites. At the Pueblos sinkhole, a platform overlooks the Camuy River, passing through a network of cave tunnels.
  • Las Cabezas de San Juan Nature Reserve (tel. 787/722-5882): This 316-acre (128-hectare) nature reserve about 45 minutes from San Juan encompasses seven different ecological systems, including forestland, mangroves, lagoons, beaches, cliffs, and offshore coral reefs. Reservations are necessary to enter, and the park is open 5 days a week (Wed-Sun). The park staff conducts tours in Spanish and English from 9am through 2pm. Each tour lasts 2 1/2 hours and includes rides on trolleys and a walk along boardwalks through oceanfront mangrove forest. Tours end with a climb to the top of the still-working 19th-century lighthouse for views over Puerto Rico's eastern coast and nearby Caribbean islands. Call to reserve space before going, as bookings are based on stringent restrictions as to the number of persons who can tour the park without damage to its landscape or ecology. One of the finest phosphorescent bays in the world is located here, and local tour operators take you in a kayak or electronic boat to experience the animals' glow firsthand during nighttime tours.

Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.