Blackness Castle Magazine was built in 1870 together with a munition pier. This was a central magazine used to re-supply the various coastal defence batteries in the Firth of Forth, particularly those on islands, which included:
Inchkeith Island
Kinghorn Battery
Cramond Island
Inchmickery Island
Inchcolm Island
Braefoot Battery
Dalmeny Battery
Inchgarve Battery
Carlingnose Battery
Coastguard Battery
Downing Point
Hount Point Battery
The iron trestle pier included a pier head which mounted a hand operate crane for lifting munitions to and from vessels. The site was decommissioned in 1912 but the War Department returned during World War 1.
The Munitions Pier was separated by a drawbridge in front of the gateway. This is believed to be one of the last drawbridges built at British fortifications.