Environment

Roughly half the size of New Jersey, this U.S. commonwealth with 272 miles (438km) of Atlantic and Caribbean coastline sits strategically some 1,000 miles (1,610km) southeast of Florida at the hub of the Caribbean chain of islands. You'll probably fly in and out of San Juan at least once if you're doing much touring in the region. And with a 2-year, $2.8 million project that restored its waterfront, this oldest capital city under the U.S. flag is also the world's second-largest home port for cruise-ship passengers.

Puerto Rico has experienced many political changes since the days of its first Spanish governor, Juan Ponce de León, the conquistador who sailed with Columbus and who tried in vain to find a fountain of youth in Florida. With nearly 500 years reflected in its restored Spanish colonial architecture, Old San Juan is the Caribbean's greatest historic center.

Puerto Rico is the most easterly and the smallest of the four major islands that form the Greater Antilles. The other three are Cuba, Jamaica, and Hispaniola (which is home to two nations, Haiti and the Dominican Republic). Surrounded by the Atlantic Ocean to the north and the Caribbean Sea to the south, Puerto Rico is flanked by a trio of smaller islands -- Vieques and Culebra to the east and Mona to the west -- which are its political and geologic satellites.

The island's terrain ranges from palm-lined beaches on four coastlines to rugged mountain ranges, gently rolling hills, and dry desert-like areas. There are 20 designated forest reserves in Puerto Rico.

Beaches

The island has dozens of miles of sandy beaches, some long and straight, others broken into coves by headlands. On the northern coast, the Atlantic waters are often more turbulent than those along the more tranquil southern coast.

Towering Mountains

Besides the beaches, the island's most noteworthy geological feature is the Cordillera -- the towering mountains that rise high above its central region. Geologists have identified the island's summits as the high parts of a chain of mountains whose mass is mostly submerged beneath the sea. These mountains are some of the oldest of the many landmasses in the West Indies.

What makes the mountain altitudes even more impressive is the existence, about 75 miles (121km) to the island's north, of one of the deepest depressions in the Atlantic, the Puerto Rico Trough. Running more or less parallel to the island's northern shoreline, it plunges to depths of up to 30,000 feet (9,000m). Although not as obvious as this trench, the sea floor a few miles from the island's southern coast also drops off, to nearly 17,000 feet (5,100m) below sea level. Geologists have calculated that if the base of this mountain chain were at sea level, it would be one of the highest landmasses in the world. Puerto Rico's highest summit -- Cerro de Punta, at 4,389 feet (1,317m) -- would exceed in altitude Mount Everest, the world's tallest peak.

Most of Puerto Rico's geology, especially its mountain peaks, resulted from volcanic activity that deposited lava and igneous rock in consecutive layers. To a lesser degree, the island is also composed of quartz, diomites, and, along some of its edges, coral limestone.

El Yunque & The Other Forest Preserves

The mountains are home to the island's greatest natural attraction, El Yunque (tel. 787/888-1810 or 787/888-5646 for information), a 45-minute drive east of San Juan. Given national-park status by President Theodore Roosevelt, this 28,000-acre (11,330-hectare) preserve is the only tropical rainforest on U.S. soil and is protected by the U.S. Forest Service.

Today, El Yunque offers visitors close encounters of the natural kind, from picnics amid rare flora and fauna to hikes along scenic trails. Encompassing four distinct forest types, it is home to 240 species of tropical trees; flowers, including more than 20 kinds of orchids; and other wildlife, including millions of tiny tree frogs whose distinctive cry of coquí (pronounced "ko-kee") has given them their name.

Puerto Rico also has 19 other forest preserves. Directly east of San Juan lies Piñones Forest, which contains the island's largest mangrove forest. West of Ponce, Guánica Forest borders several white-sand beaches and the historic bay where U.S. troops first landed in 1898 during the Spanish-American War. Cambalache Forest, east of Arecibo, contains plantations of eucalyptus, teak, and mahoe trees. The driest vegetation and expansive views to the west coast are found in Maricao Forest. Few visitors will have time for a forest preserve other than El Yunque. If you do, make it Toro Negro Forest Reserve, which straddles the peaks of the Cordillera in the center of the island and boasts the island's tallest peak, with stunning drops to the Caribbean and the Atlantic. All of these forests are open to visitors, and several have picnic areas and campsites.

The Karst Country & Rio Camuy Caves

One of the most mysterious areas of Puerto Rico is the Karst Country. One of the world's strangest rock formations, karst is formed by the process of water sinking into limestone. As time goes by, large basins are eroded, forming sinkholes. Mogotes, or karstic hillocks, are peaks of earth where the land didn't sink into the erosion pits. The Karst Country lies along the island's north coast, northeast of Mayagüez, in the foothills between Quebradillas and Manatí. The region is filled with an extensive network of caves. One sinkhole contains the 20-acre (8-hectare) dish of the world's largest radio/radar telescope at the Arecibo Observatory.

Reached by Route 446, the Guajataca Forest Reserve is found here, offering some 25 miles (40km) of trails that take you through some of the most rugged parts of this country.

Eons ago, one of the world's largest underground rivers carved the Río Camuy Caves in northwest Puerto Rico, which experts today consider to be among the most spectacular caves on earth. The Río Camuy Caves contain evidence of occupation long before the island was sighted by Columbus in 1493. The first professional explorers of the system were led to the site by local boys already familiar with some of the entrances.

Off-Island Islands

Three offshore islands -- Mona, Vieques, and Culebra -- are well worth exploring.

Despite bad publicity generated by U.S. Naval bombing exercises, Vieques is the most developed of the offshore islands from a tourist prospective. Shaped like a long fish, its spine is a mountain range that separates it lengthwise from west to east. At 21 miles (34km) in length and 5 miles (8km) in width, Vieques is the largest landmass of the Spanish Virgin Islands.

Although the Spanish referred to both Vieques and Culebra as las islas inútiles (the useless islands) because there was no gold to be mined there, they are islands bonito for the visitor. Offering the lazy life, Vieques has top-notch inns and excellent and relatively undiscovered dining. Most visitors come here to escape and to enjoy the gorgeous beaches.

Even sleepier than Vieques is the smaller and less developed island of Culebra. It's a place where you have to drive carefully to let Mother Hen cross the road. At a distance of some 17 miles (27km) east of the Puerto Rican port of Fajardo, Culebra, from the geologist's point of view, is closer to the U.S. Virgin Islands than "mainland" Puerto Rico. St. Thomas lies only 12 miles (19km) to the east.

With its rugged peaks, sandy beaches, and offshore caves, Culebra can quickly bring out the beach bum in you. Many visitors, in fact, have settled there. As two culebrenses (the name of the islanders) confided to us, "If you come here with gringo uptightness, you'll lose it in a few days."

Much of Culebra is a national wildlife refuge -- so much so that in summer many of the beaches are closed by the U.S. Fish and Wildlife Service because they are nesting grounds for endangered sea turtles.

A unique environment can be found on Mona Island, 50 miles (81km) west of Puerto Rico. Like the Galapagos Islands, this untouched island has species that are not found elsewhere. Mona is a protected island, under the management of the U.S. National Park Service and the Puerto Rican Natural Resources Department. Accessible by a sometimes difficult, long, boat ride, the island is available for sport diving to those who are willing to rough it.