A typical Caribbean mid-afternoon at Castillo San Felipe del Morro, San Juan, Puerto Rico. Construction of the original structure was finished in 1587, becoming the largest Spanish fortification in the Americas. Bosting 450 cannons, the fort successfully repelled numerous attacks by foreign powers, like the British and Dutch, for over 200 years. With the Spanish defeat in the Spanish-American War of 1898, the island of Puerto Rico became an American territory. After this, the fort was used by the U.S. Army to guard San Juan Bay during the first two World Wars.