The oldest Spanish fort in the New World, El Morro was built to protect San Juan, Puerto Rico from attacks from the sea and to control entry to the harbour. The fort is called San Felipe del Morro. The name by which the fort is commonly known, El Morro, is the Spanish word for headlandwhich it refers to the headland on which the fort stands.Construction began in 1539 and went through several phases of building over the next 248 years. The external walls of El Morro swallowed the original construction as the site grew larger.Eventually standing six stories tall, with 140 ft (42 meters) high walls that are sometimes 18 ft (5 meters) thick, El Morro was completed in 1787. On the other side of the harbour is another fortress, San Juan de la Cruz, better known as El Cañuelo – together the forts were able to catch potential invaders in a deadly crossfire. Despite the defenses, El Morro did come under attack. Among them was English pirate Sir Francis Drake in 1595. In a sea-based attack that ended in failure, there is a story that a cannonball fired from El Morro passed clean through the cabin of his flagship. Following this attack, defenses were reinforced. This led to the construction of the city wall between 1630 and 1678. Also, another fortress was designed to protect against attacks from the east. Construction on San Cristóbal began in 1634.The final attack on El Morro was during in 1898. During the Spanish-American War, US Warships fired on the lighthouse and destroyed it. Under the United States El Morro continued to be used by the military. Gun emplacements were added during World War I, and when the United States entered into World War II in 1942, an observation post and underground bunker were added
