Old San Juan sits on the western half of a small islet, connected to the mainland by causeway. The walls of Castillo San Cristóbal separate the old city from the district of Puerta de Tierra, base of central government offices including The Capitol (El Capitolio) .
Across the causeway are the beachfront hotels, casinos and condominiums of Condado. This was once San Juan's wealthiest neighborhood (the Vanderbilts had a summer home here). The quiet beaches of Ocean Park and Punta Las Marías are popular with windsurfers and sun worshippers. Farther east along the coast is Isla Verde and its mile-long stretch of high-rise luxury resorts. Visitors who fly into San Juan see this area first; it's the home of Luis Muñoz Marín International Airport.
San Juan's first airport was southeast of the old city on the peninsula of Isla Grande, where the 113-acre Puerto Rico Convention Center opened in 2005. The largest and most technologically advanced meeting facility in the Caribbean, this waterfront complex includes hotel rooms, office buildings and retail and entertainment venues.
East of Isla Grande are the suburbs of Miramar, which overlooks the Condado Lagoon, and Santurce, the city's former marketplace. La Placita del Mercado de Santurce is still a popular place to buy fresh fruits and vegetables, wooden santos and handmade mundillo lace. Today, Santurce is the city's cultural heart, boasting the Luis A. Ferré Performing Arts Center, the Art Museum of Puerto Rico (Museo de Arte de Puerto Rico) and Puerto Rico Museum of Contemporary Art (Museo de Arte Contemporáneo de Puerto Rico) .
Southeast of Santurce is the downtown business district, Hato Rey. Here are the high-rise banking and financial buildings, along with the Plaza las Américas, the Caribbean's largest indoor shopping mall. Hato Rey's sports complex includes the 18,000-seat Hiram Bithorn Baseball Stadium (former home of the Montreal Expos) and the Roberto Clemente Coliseum for basketball and other indoor events. A venue for concerts and entertainment, the José Miguel Agrelot Coliseum, opened in Hato Rey in 2004.
Farther south, Río Piedras is home to the University of Puerto Rico with its museums and art galleries and the 300-acre Botanical Garden of the University of Puerto Rico (El Jardín Botánico) . While in Río Piedras, you can visit the home of the island's first democratically elected governor, Fundación Luis Muñoz Marín , at Trujillo Alto. Some of the city's wealthiest neighborhoods are found in Guaynabo, where Juan Ponce de León built the island's first settlement in 1508. The ancient foundations are visible at Caparra Ruins Historical Museum and Park .
South across the harbor from Old San Juan by ferry is the suburb of Cataño, which most visitors know for the “Cathedral of Rum” and the Casa Bacardí Visitor Center . Nearby Bayamón, the second most populous city on the island, has been a sugar-producing center since 1548.
Driving east from San Juan, you'll pass the famed Hipodromo Camarero horse-racing track at Canóvanas . Beyond is the town of Río Grande, gateway to the El Yunque National Forest . It's a 45-minute trip from the narrow streets of Old San Juan to this vast rain forest preserve in the Luquillo Mountains—and if you really want a change of elevation, hike to the top of 3,533-foot El Yunque.