[itslennysfault]

Montreal has one: https://www.mtl.org/en/experience/guide-underground-city-sho...

I grew up in Chicago and lived in Montreal for a while. Theirs is WAAY better than Chicago's.

[zoomablemind]

+1. Very functional and mostly clean system. Not that Montrealers are afraid of cold. Not sure how many businesses are still operating there post-pandemic.