Kiel's surviving naval infrastructure and the Oslo ferry route

Does First World War naval infrastructure survive at Kiel, and does the Kiel-Oslo ferry follow the route used by the 1940 invasion force?

The ferry probably uses broadly the same geographic route, while modern facilities occupy some historic naval sites. The answer does not claim enough local knowledge to identify surviving First World War structures confidently.

The panel sees little reason for the modern ferry to take a radically different path between Kiel and Oslo because geography constrains the practical route. That makes broad overlap with the 1940 invasion movement plausible. The infrastructure answer is more cautious: later naval and port facilities stand on sites used in the First World War, but shared location does not prove that the original structures survive. The museum and dockyard areas have not been examined closely enough here to support a confident inventory. Continuity of place and route should therefore be kept separate from verified survival of particular historic buildings.