Main article: San Juan, Puerto Rico

Old San Juan is the historic colonial district of San Juan, Puerto Rico.

The Old San Juan district is located on a small island connected to the mainland of Puerto Rico by bridges and a causeway. The city is characterized by its narrow cobblestone streets and colorful buildings which date back to the 16th and 17th century when Puerto Rico was a Spanish possession. The distric is also characterized by numerous public plazas and churches including The Cathedral of San Juan Bautista , which contains the tomb of the Spanish explorer Juan Ponce de León.

The oldest parts of the city remain partly enclosed by massive walls. Several defensive structures and notable forts, such as Fort San Felipe del Morro and Fort San Cristóbal, and El Palacio de Santa Catalina, also known as La Fortaleza acted as the primary defenses of the settlement which was subjected to numerous attacks. La Fortaleza continues to serve also as the executive mansion for the Governor of Puerto Rico. Many of the historic fortifications are part of San Juan National Historic Site.