Guarded iron gates mark the imposing La Fortaleza. Dating from 1533, it's the oldest executive mansion in continuous use in the western hemisphere. The original fortress for the young colony, La Fortaleza eventually yielded its military preeminence to the city’s newer and larger forts and was remodeled and expanded to domicile island governors for more than three centuries. There are free, 30-minute guided tours between 8:15am and 3:30pm. They include the mansion’s Moorish gardens, the dungeon and the chapel.

　　Tour schedules change daily, so call in advance to reserve a place. Be prepared for a security gauntlet, including handing over your ID – passport, driver's license – for the duration of the tour.