It's only the size of Connecticut, but Puerto Rico pulsates with more life than any other island in the Caribbean. To the beat of bomba, there's a party going on here 24 hours a day.  The 4 million people who live here believe that having fun is one of the reasons they were born on this dazzling island. One of the most popular tourist destinations south of Florida raises the rainbow flag to a diverse heritage, beginning with the early settlers, the Taíno Indians. Their culture later gave way to African and Spanish influences.

Puerto Ricans have a lot to boast about, including 260 miles of sandy beaches; the third-largest underground cave system on earth; and the world's largest radio telescope, which sends signals into outer space 24 hours a day, hoping ET will call in for a "close encounter." And don't forget its lush Caribbean forests, including the only rainforest (El Yunque) on U.S. territory. There are an astonishing nine protected nature reserves on this so-called "Island of Enchantment," with species of wildlife you won't find anywhere else in the world.

A clue to the Puerto Rican soul is reflected in the national anthem, "La Borinqueña." Most national anthems around the world sing of military muscle and a triumph over enemies. Not so "La Borinqueña." It sings of "a flowering garden of exquisite magic . . . the daughter of the sea and the sun." Get to know this garden and the people who call it home.

One of the oldest cities in the Americas, San Juan presents two different faces. On one hand, the charming historic district, Old San Juan, is strongly reminiscent of the Spanish Empire. On the other hand, modern expressways outside the historic district cut through urban sprawl to link towering concrete buildings and beachfront hotels resembling those of Miami Beach.

Old San Juan is a 7-square-block area that was once completely enclosed by a wall erected by the Spanish with slave labor. The most powerful fortress in the Caribbean, this fortified city repeatedly held off would-be attackers. By the 19th century, however, it had become one of the Caribbean's most charming residential and commercial districts. Today it's a setting for restaurants and shops. Most of the major resort hotels are located nearby, along the Condado beachfront and at Isla Verde.