Located on the south coast of Devon, Plymouth is the largest city on the southwest peninsular and is home to the largest naval base in western Europe. The primary harbour authority is the MoD who operate the port under the 1865 Dockyard Ports Regulation Act and the associated Dockyard Port of Plymouth Order 1999.  Three separate statutory harbours (ABP Millbay:Sutton Harbour Authority and Cattewater Harbour Commissioners) operate within the Dockyard Port.