San Juan National Historic Site
- Address: Avenida Muoz Rivera
- District of Old San Juan in San Juan
- Hours: Castillo San Cristobal and Castillo San Felipe del Morro are open to the public everyday 9:00am to 6:00pm except on Thanksgiving Day, Christmas Day and New Year's Day
The Gibraltar of the Caribbean
Puerto Rico's geographic position at the western edge of the Caribbean made San Juan one of the key frontier outposts of Spain's West Indies dominions. San Juan National Historic Site includes Castillo San Cristobal, Castillo San Felipe del Morro, Fortin San Juan de la Cruz known locally as El Canuelo, and three fourths of the city walls. - NPS