The North Lines, which is an expansive ditch and profiled rampart with banquette, connects the Citadel, North Centre Bastion and the Drop Redoubt of the Western Heights, Dover. It was excavated/constructed between 1804 and 1816 to close the gap between the fortifications on the northern side and thereby deny an attacking force access to the weakest positions of the Citadel and the Drop Redoubt. (location accurate to the nearest 1m based on available information).