El Morro (fort San Felipe Del Morro)
Officially known as Fuerte San Felipe del Morro, this fort sits atop a high promontory overlooking the entrance to San Juan Bay. It is the result of the efforts of many different Spanish engineers over a period of more than 200 years and is one of the largest forts built by the Spaniards in the Caribbean. Although the foundations were laid in 1539, the six-level fort was not considered completed until 1787. During World War II, the U.S. government added an annex of its own design on top of the fort. This massive structure suffered countless attacks from the likes of Sir Francis Drake in 1595 and the Dutch fleet in 1625. In 1898 American ships fired on it during the Spanish-American War, destroying its lighthouse, which was later restored. Visit hidden passages, aim your camera on the cannons that still guard the harbor, and gaze over the 60-foot tall walls at the ocean. Stroll on the lawns where soldiers once marched and watch the children flying their kites in the afternoon sea breezes. The fort can be explored everyday from 9:00 am to 5:00 pm from June to November and 9:00 am to 6:00 pm December to May either on your own or on one of the ranger programs that take you through the fortification and out onto the picturesque garitas, or lookout towers. Fort San Felipe del Morro is a UNESCO World Heritage Site.