Early plans were drawn up for the Drop Redoubt Fort following the advent of war between England and France in 1778. The extent of these earthen defences, the first to be built on the Western Heights, is not clear due to the scant nature of documentation but it has been assumed that they were on a small scale. The eastern fort - on the site later taken by the Drop Redoubt - is depicted on a plan dating to 1787 as an irregular four-sided work surrounding a central guardhouse. (location accurate to the nearest 50m based on available information)