It is located within the Flat Bastion, a fortification that projects from the 16th century Charles V Wall at the former southern limit of the city.

Flat Bastion Magazine was constructed to store gunpowder, but eventually lay abandoned for years.

[1][2] It is within the eastern portion (highlighted in map below) of the Flat Bastion, one of the fortifications of Gibraltar that projects southward from the Charles V Wall and constituted part of the defences of the former southern limit of the city.

The doors were fabricated from oak that dates back five or six centuries, well before the British version of the magazine was built.

[10] Gibraltarian Freddie Gomez, whose interests include history and geology, has looked after Flat Bastion Magazine for years, and believes that it dates back to before 1873.

[12][13][14] During a two-week training period in Gibraltar, the 150 (Yorkshire) Transport Regiment (Volunteers) from Doncaster and Kingston upon Hull spent a day at the Flat Bastion Magazine.

[9] Gomez, who has been described as "entertainingly garrulous and delightfully eccentric," is primarily self-taught and knowledgeable on the topic of Gibraltar's geology.

[10] While visits to the facility are currently by appointment only, it is anticipated that the Flat Bastion Magazine will be opened to the public.