O'Hara's Battery: A 19th-century Gibraltar gun emplacement

Located on the British Overseas Territory of Gibraltar, O'Hara's Battery, built in 1890, stands at the highest point of the Rock, near the southern end of the Upper Rock Nature Reserve, close to Lord Airey's Battery. The battery was named after General Charles O'Hara, a former governor of Gibraltar who served from 1795 until his death in 1802. It was constructed on the former site of a watchtower that had earned the name O'hara's Folly; after the tower was demolished in 1888, the battery was completed and the first 6-inch breech loading gun was installed.

The battery remained in active use during World War II and is now open to the public as a tourist attraction. Visitors can explore the underground magazine, the engine room, and the gun turntable. The battery houses a 9.2-inch Mark X BL gun, which was mounted on the battery in 1901 to defend the Strait of Gibraltar. This gun had a range of 29,000 yards, meaning it was theoretically capable of reaching the African shore, only 14 miles away.

The gun was exposed to the elements for more than three decades before a steel shield was installed in 1934. The battery was last fired during a training exercise in 1976. Today, the site is listed with the Gibraltar Heritage Trust and is managed on a day-to-day basis by a private company under the supervision of the Gibraltar Tourist Board.

Sources: Wikipedia, OpenStreetMap, Wikidata, Wikimedia Commons