ridge between the Citadel and Drop Redoubt; the South Lines, descending from the Citadel to the Old Folkestone Road (where a bridge across the defensive ditch provided access to the fortress, by way of the South Military Road, as well as to the harbour beyond); and the North-East Line, running east from the Drop Redoubt. During the building of the defensive lines (1809-16) a tiered bulwark, the 'North-West Bastion', was built on the edge of the Citadel flanking the northern slope of the Heights. At the same time the 'North-Centre Bastion' was built, halfway along the earthworks between the Citadel and Drop Redoubt. As part of the construction of the North Lines a North Entrance was built, between the Drop Redoubt and North Centre Bastion, giving access to the Heights by way of the North Military Road. After 1858, a further 'Detached Bastion' was built immediately to the north of the North Centre Bastion (which was itself rebuilt and strengthened), to the designs of Captain Edmund Du Cane. (The bastions enabled flanking fire (by both muskets and artillery) along the length of the North Line.) At the same time, the Citadel was extended to the west (the 'Western Outworks') with further casemated barracks provided within the new ramparts. Also at this time, following the Royal Commission of 1859, the North and South Lines were strengthened and the North-East Line rebuilt on a different alignment, more effectively closing off that end of the site between the Drop Redoubt and the cliffs. Furthermore, the North Entrance was rebuilt and strengthened (necessitated by the rebuilding of the Lines); it was approached by way of a twisting path through the tenaille and lifting and falling bridges across the ditches. A new South Entrance was also provided to the south (built where the South Military Road crossed a new extension to the South Lines, close to the junction with Citadel Road). Also known as Archcliffe Gate, this monumental stone gatehouse was demolished in the 1960s. As well as helping protect the Heights from landward attack, the earthworks served to enclose a sizeable area of land (lying between the Citadel and the Redoubt, the North Lines and the escarpments to the south and east. This could accommodate a large body of troops accommodated in tents; it continued to be used for large-scale parades and assemblies of troops prior to embarkation during the First World War. Barracks