Bosque Estatal de Piñones [1]: Between the San Juan airport and the town of Loíza, this untouched parcel of natural beauty features several long stretches of wilderness beach, salt flats, mangroves, lagoons, and tropical forest, as well as six miles of bike path and a cluster of food kiosks serving some stellar Puerto Rican fast-food fare.
El Yunque Caribbean National Forest [2]: Puerto Rico’s crowning jewel of natural treasures, the Caribbean National Forest is a 28,000-acre reserve that encompasses a rain forest, hiking trails, observation towers, waterfalls, and natural pools.
Las Pailas [3]: This natural water slide is formed by a mountain stream cascading over a smooth but rocky descent that bottoms out in a chest-deep pool of crystal-clear water.
Balneario La Monserrate [4]: Considered by many to be the main island’s most beautiful beach, this publicly maintained facility, commonly called Playa Luquillo, features gentle waters, a wide crescent-shaped strip of sand, and a palm grove, which create the picture-perfect idyll of tropical paradise.
Reserva Natural Las Cabezas de San Juan [5]: Despite its small 300-acre size, the Fajardo nature reserve features seven different ecosystems, including coral reef, turtle grass, sandy beach, rocky beach, lagoon, dry forest, and mangrove forest. Its mangrove-enveloped Laguna Grande is bioluminescent — kayak here on a moonless night to see the water glow green, thanks to the harmless microscopic organisms that live here. It also boasts an 1880 lighthouse.
Links:
[1] http://www.moon.com/destinations/puerto-rico/east-coast/loiza-and-pinones/sights/bosque-estatal-de-pinones
[2] http://www.moon.com/destinations/puerto-rico/east-coast/rio-grande/el-yunque-caribbean-national-forest
[3] http://www.moon.com/destinations/puerto-rico/east-coast/luquillo/las-pailas
[4] http://www.moon.com/destinations/puerto-rico/east-coast/luquillo/balneario-la-monserrate
[5] http://www.moon.com/destinations/puerto-rico/east-coast/fajardo/sights/reserva-natural-las-cabezas-de-san-juan