Also known as the Hexagonal Tower, this limestone structure was designed to protect the front wall and landing road sides of the fort. Mounting two, 12-pounder iron cannons on the top floor, the tower could deliver blasts of canister shot the length of each wall. The two lower floors were built with embrasures, or long slits, for muskets in their outer walls.
Colonel Snelling originally intended to build this defensive position as a blockhouse within the adjacent Commissary Warehouse. An 1821 map shows this feature, which was modified during construction.
The South Battery is the least altered of the fortís four original buildings. During much of the 19th century, it was used for storage, though its final military use was as a latrine for the nearby laundress quarters. In later years, a concrete floor was poured and the tower used to house an electrical transformer.
When archaeologists broke through this floor in the 1960s, they found quantities of leather military accouterments preserved in the mud below. They also found a chamber carved into the bedrock which likely held ammunition for the cannons above.
The battery has been carefully restored to its 1820s appearance and now features functioning replicas of its original cannons.