Fort Ross, located on the coast of California, was a hub for trade and exploration in the 19th century.
San Carlos Fortress, a majestic structure overlooking the town of Perote.
San Juan de Ulúa is a large complex of fortresses, prisons and one former palace on an island overlooking the seaport of Veracruz, Mexico.
Russian Fort Elizabeth is a National Historic Landmark and the last remaining Russian fort on the Hawaiian islands.
San Salvador de la Punta Fortress guards the entrance to Havana Bay, opposit the Morro Castle.
The Fortress of the Immaculate Conception is a bastion fort on the shores of the San Juan River.