Early 19th century magazine and ordnance depot, Upnor. Built in a former gravel quarry the depot was constructed in c. 1813 to hold and test gunpowder. It replaced an earlier store south of Upnor Castle which itself replaced the Castle as a gunpowder store. The depot comprised 'A' magazine (with its ancilliary structures), and subsequently 'B' magazine which had capacity for 23,000 barrels of powder. In 1862 a new shell store was built north of 'B' magazine. The depot was placed under the control of the Admiralty in the 1880s and was known as Royal Naval Armaments Depot (RNAD) Upnor. By 1884 the site had an extensive internal railway system and was linked externally to Chattenden. In 1895 it was further extended with a guncotton shop. At about the same time the site was extended to the north for a new shell store, mine store and offices. New shell filling rooms were constructed in 1909 and additional sheds built during the First World War. By 1964 the site was no longer needed and most buildings were demolished. Today 'B' magazine, the traverse to the former shifting house and a First World War sentry post survive.