Montréal also has a nice 32km+ of underground network. It includes : 4000+ shops, restaurants; 20+ museum; Universities, school, libraries, hotels, corporate towers, etc..[1]

A full map is available here: https://portail-m4s.s3.montreal.ca/pdf/vm_16722_00_planreso_...

Wikipedia article: https://en.m.wikipedia.org/wiki/Underground_City,_Montreal

[1] https://montreal.ca/articles/reso-le-reseau-souterrain-de-mo...