One of those adventure days looking for points of interest to drone when we came across this ruin. Turned out to be an old fort. Fort Macomb in fact. Wikipedia: Chef Menteur Pass is a water route from the Gulf of Mexico to Lake Pontchartrain and the lakeshore of New Orleans. (The other route is the Rigolets; both straits connect Pontchartrain to the Gulf via Lake Borgne.) An earlier fort at the site was called Fort Chef Menteur. The United States built the current brick fort in 1822, just seven years after British forces invaded the New Orleans area from the sea, at the close of the War of 1812. It was named Fort Wood in 1827 renamed Fort Macomb in 1851, for General Alexander Macomb, former Chief of Engineers and the second Commanding General of the United States Army. The small fort shaped like a pie wedge has a curved front facing the channel; the curve overlaps the two straight walls, forming demi-bastions. At the salient of the two straight walls is a full bastion facing landward. The fort was surrounded by two wet ditches (moats) with extensive outworks between the ditches. On the parade stands a citadel, a defensive barracks. A Confederate States Army garrison took control of and occupied the fort starting on 28 January 1861 early in the American Civil War. In 1862 the Union Army regained control of the fort and also occupied New Orleans. In 1867 the barracks caught fire, after which the fort was largely abandoned by the U.S. Army. It was decommissioned in 1871.