The island’s most striking example of colonial architecture is Fuerte San Felipe del Morro. Named in honor of King Phillip II, El Morro (the promontory) rises majestically above the sea, overlooking the Atlantic Ocean and San Juan Bay. Built to protect San Juan from maritime attack, the fortress was begun in 1539 and completed in 1589. However, most of the existing walls were added in a period of tremendous construction from the 1760s to the 1780s. Rising 140 feet above the sea, its 18-foot-thick wall proved a formidable defense. It fell only once, in 1598, to a land assault by the Earl of Cumberland’s forces. El Morro is a six-level maze of tunnels, dungeons, barracks, outposts and ramps. Its small, circular sentry turrets called “garitas” have become a national symbol.
Another fortress is Castillo de San Cristóbal, El Morro’s partner in the city’s defense. Built in 1634 and completed in 1771, it was considered the Gibraltar of the West Indies and is the largest fortification ever built by the Spaniards in the New World. If its height and size (150 feet and 27 acres) hadn’t been sufficient to intimidate enemies, its intricate modular design surely would have foiled them. A strategic masterpiece, San Cristóbal features five independent units, separated by moats and connected by tunnels, each fully self-sufficient should the others fall.
Other fortifications that surround Old San Juan include La Fortaleza (now the governor’s palace), the small fort of El Cañuelo, bastions, powder houses and three-fourths of the city walls. Together with El Morro and San Cristóbal, they have been designated a World Heritage Site.