Familiarly known as the "Old Arsenal" and "Old Spanish Arsenal" the 1838 powder magazine on the state capitol grounds in Baton Rouge, Louisiana is an excellent example of nineteenth century non-fortification military architecture. Although the magazine has suffered several obvious modernizations and restorations both the protective perimeter wall and powder storage building retain much of their original character and many distinctive architectural features that are useful to an understanding of how buildings were designed and constructed for the long term storage of gun-powder.