A similar but much more active 100+ year old tunnel in Hamburg: https://en.wikipedia.org/wiki/Elbe_Tunnel_(1911) https://en.wikipedia.org/wiki/Elbe_Tunnel_(1911

A similar but much more active 100+ year old tunnel in Hamburg: https://en.wikipedia.org/wiki/Elbe_Tunnel_(1911) https://en.wikipedia.org/wiki/Elbe_Tunnel_(1911) That one allows both cars and pedestrians. Worth seeing while in Hamburg (along with the miniature model railway museum https://en.wikipedia.org/wiki/Miniatur_Wunderland https://en.wikipedia.org/wiki/Miniatur_Wunderland - a visit there inspired Sid Meier to re-create Railroad Tycoon).