Fuerte San Felipe del Morro (El Morro)

Protecting the entrance to San Juan Bay, the fort, commonly referred to as El Morro, is dramatically perched above the sea on a point of land jutting out into the ocean. A designated National Historic Site and a UNESCO World Heritage Site, El Morro was built in 1539, with ongoing construction for 250 years, and is one of the largest Spanish forts in the Caribbean. Much construction took place between the 1760s and 1780s, when many of the present walls were added. The fort today is a maze of ramps, outposts, barracks, dungeons, and tunnels, dotted with small, circular sentry boxes called "garitas." These garitas are unique to Puerto Rican forts and have become a national symbol.
The area approaching the fort is open lawn and there are incredible views from every side, either back towards San Juan, including a view to the famous cemetery, or out to sea. While it is a fair distance, visitors can easily walk out to the fort from the streets of Old San Juan.