The Brunkeberg Tunnel in Norrmalm, Stockholm, is a 231-metre-long passageway for pedestrians through the esker Brunkebergsåsen. The tunnel was inaugurated in 1886 by King Oscar II.
Wikipedia https://en.wikipedia.org/wiki/Brunkeberg_Tunnel
Coordinates 59°20'13.941" N 18°3'58.717" E
