Plan de la rade de Cherbourg : [dessin] / projetée par Mr de Cessard, ingénieur des Ponts et Chaussées
Map of the rade of Cherbourg by Mr de Cessard
Cherbourg Harbour (French rade de Cherbourg; literally, the roadstead of Cherbourg) is the largest artificial harbour in the world, with a surface area of around 1,500 hectares. Historically it has been used for mercantile shipping as well as a naval base.
It was begun in 1783, with its central harbour wall was completed in 1853 - this was 3.64 km long, an average of 100m wide at its base and an average of 12 m wide at its top, and sited 4 km from the coast. Three forts were added to the central wall in 1860. This and the two other harbour-walls stretch for more than 6 km. The eastern opening into the harbour is 950 m wide and the western one 2.3 km wide. The harbour’s maximum depth is 13 m at low tide.