Opened in 1933, this tunnel serves both pedestrians and cyclist. It connects the older part of Antwerp with the newer one. There is a large elevator, but you can also opt to go down or up by the wooden escalator. It's one of the quickest ways to get from one side to another - it only takes about 10 minutes on foot.
Wikipedia https://nl.wikipedia.org/wiki/Sint-Annatunnel
Coordinates 51°13'14.41" N 4°23'18.096" E