Old San Juan's 16th-century cobblestone streets, ornate Spanish town houses with wrought-iron balconies, ancient plazas, and eclectic museums are all repositories of the island's colorful history. Founded in 1521 by the Spanish explorer Juan Ponce de León, Old San Juan sits on an islet separated from the "new" parts of the city by a couple of miles and a couple of centuries. Ironically, its culture is youthful and vibrant, reflecting the sensibilities of stylish professionals, a bohemian art crowd, and university students who populate the streets. You'll find more streetfront cafés and innovative restaurants, more contemporary art galleries, more musicians playing in plazas, than anywhere else in San Juan.
Old San Juan slopes north, uphill, to Calle Norzagaray, which runs along the Atlantic shoreline and connects Castillo San Cristóbal to El Morro, the Old City's twin defensive bastions. On the north side of Calle Norzagaray you'll find a small neighborhood tucked beneath the city walls tight up against the ocean—this is La Perla, a rough area that you would be wise to avoid. The west end of the Old City overlooks San Juan Bay, and it's here that the rugged, towering walls of the original city are most evident. On Old San Juan's south side, along Calle Gilberto Concepción de Gracia, you'll find the commercial and cruise-ship piers that jut into San Juan Harbor.