San Juan is Puerto Rico's capital and the largest city in the Caribbean, with a population of about one million. It sits on the northeastern coast of the island, and the contrast between its parts is pronounced: Old San Juan — a 7-square-block walled city on a small peninsula — is one of the best-preserved Spanish colonial towns in the Americas, while the resort strip of Condado and Isla Verde is all high-rise hotels and beach clubs.
Old San Juan was founded in 1510 and its cobblestone streets, pastel-painted buildings, and massive fortifications are genuine, not reconstructed. The two principal forts — El Morro, commanding the entrance to San Juan Bay, and San Cristóbal, the largest Spanish fort built in the Americas — are managed by the US National Park Service and together form one of the most significant military sites in the hemisphere. Both are UNESCO World Heritage Sites. La Fortaleza, the governor's mansion built in 1540, is still in use and holds the record as the oldest continuously occupied executive mansion in the Americas.