The moat and the ramparts are the two basic components of the fortress the West Enceinte.
The enceinte streches 14,3 kilometres from the Køge Bay south of Copenhagen to the Utterslev Mose, (a bog) west of the city. The enceinte was built in the period 1888 to 1892.
Very simply, the surface was mirrored so that the excavated material from the moat became the rampart
2,5 millions m3 of soil was moved over the 14,3 kilometres, almost by hand.
The moat was 16 meters wide and 2.5 meters deep. In the middle there was a 1 meter deep channel (cunette), so the wading depth here was 3.5 meters. The water level was kept constant by a series of dams.
The water came from the northern Utterslev Mose (bog area) and the surplus water was discharged into the Køge Bay at the sputhern end of the moat.
A few civilian bridges and some bridges used by the army crossed the moat and the ramparts.