La Fortaleza

La Fortaleza — formally the Palacio de Santa Catalina — is the official residence of the Governor of Puerto Rico and holds the distinction of being the oldest executive mansion in continuous use in the New World. Constructed between 1533 and 1540, the Spanish colonial structure was built primarily to defend San Juan's harbor, though it proved strategically insufficient and military duties were later shifted to El Morro and Fort San Cristóbal. The complex was then repurposed as the seat of colonial and, later, island government — a role it has filled for nearly five centuries. Designated a UNESCO World Heritage Site as part of the broader San Juan National Historic Site, it combines Renaissance-era fortification walls with tropical gardens overlooking the Atlantic. Weekday guided tours offer access to the ceremonial rooms and grounds.