When they strengthened the fortress in the first half of the 18th century, the storage of gunpowder was the main issue. So, six small gunpowder stores with bombproof sandstone vaults were built around 1735/36. In 1876, the store number 2 got an earth covering for better protection and served as a wartime gunpowder store from then on. With the introduction of the explosive ammunition in the middle of the 1880s, however, it was not safe enough for this anymore. Now, only unloaded grenades were stored here.