Pentagon Barracks in Baton Rouge ( 30.455516° N, -91.189349° W)
In 1779, the British were the first to fortify the site upon which the current Pentagon Barracks inhabits. In that same year, the Spanish captured the fort, which prevented the British from controlling the Mississippi River during the American Revolutionary War. The site has since been under the flags of the Republic of West Florida, the United States, and the Confederacy. Today the site serves as apartment complex for state officials.
Old Spanish Fort (Fort St. John) in New Orleans ( 30.022480° N, -90.083143° W)
Old Spanish Fort is located on Bayou St. John near Lake Pontchartrain. It later became the site of a resort, casino and amusement park. The park, which closed in the mid-1920s, featured a water slide into the lake, a roller coaster, a prismatic fountain, and an alligator exhibit. Today the site is flanked by residential neighborhoods.
Fort Proctor, St. Bernard Parish ( 29.867405° N, -89.678150° W)
Fort Proctor is located southeast of New Orleans, on Lake Borgne, near Shell Beach. Although construction began in 1856, the ill-fated fort was never completed. A hurricane, one of many, tore through the area in 1859, halting building efforts. Before construction was ever resumed, Confederate soldiers blasted nearby levees, forcing water into the fort. The fort has remained abandoned ever since.