O'Hara's Battery is an artillery battery in the British Overseas Territory of Gibraltar. It is located at the highest point of the Rock of Gibraltar, near the southern end of the Upper Rock Nature Reserve, in close proximity to Lord Airey's Battery. It was constructed in 1890 at the former site of a watchtower that had earned the name O'Hara's Folly. The battery and tower were both named after the Governor of Gibraltar Charles O'Hara. The first gun mounted on the battery was a 6-inch breech loading gun, which was replaced with a 9.2 inch Mark X BL gun in 1901. The battery was in use during World War II and was last fired during training exercises in 1976. O'Hara's Battery has been refurbished and is open to the public. The battery and its associated works are listed with the Gibraltar Heritage Trust.

The Gibraltar Nature Reserve is a protected nature reserve in the British Overseas Territory of Gibraltar that covers over 40% of the territory's land area. It was established as the Upper Rock Nature Reserve in 1993 under the International Union for Conservation of Nature's category Ia and was last extended in 2013. It is known for its semi-wild population of Barbary macaques, and is an important resting point for migrating birds.