In 1804 plans were made to rebuild both the 'West and East Redoubts' (i.e. the Citadel and Drop Redoubt) and to link them with earthworks along the length of the Heights. By 1806 the rebuilt Citadel was surrounded by an unrevetted defensive ditch; in the centre was a set of temporary barracks huts (along with the three guardhouses). A well was sunk in 1809, to ensure a permanent supply of water in case of a siege; (a pumphouse was added in 1860).