Old San Juan Fort

San Felipe del Morro began in 1539 when the King of Spain authorized its construction, including the surrounding walls. The purpose was to defend the port of San Juan.It was also constructed to control the entry to the harbor

Many complex additional new structures were added to El Morro over the next 400 years. The outer walls are six meters thick. In 1680, Governor Enrique Enríquez de Sotomayor begun the construction of the walls surrounding the city of San Juan, which took 48 years. By the late 18th century, El Morro's walls had grown to be 18 feet (5.5 m) thick. Today El Morro has six levels that rise from sea level to 145 feet (44 m) high. All along the walls are seen the dome-covered sentry boxes known as garitas , which have become a cultural symbol of Puerto Rico itself