The (former) Royal Victoria Hospital, currently vacant. Waiting for McGill University to snatch it, as it should.
Built in phases from 1893 to the early 50's. Some of the pavilions reached 45m tall and were some of the tallest buildings in the city at the time.
Among the many medical milestones reached in these buildings, Norman Bethune and "I smell burnt toast" is perhaps it's most Canadian one.

McGill University, Montréal by
Daniel Kelly, on Flickr

Royal Victoria Hospital, Montreal, Quebec, Canada by
Striderv, on Flickr
https://upload.wikimedia.org/wikiped...Montreal_3.JPG

Royal Victoria Hospital by
Stephane Venne, on Flickr

"Ross Memorial Pavilion and Maternity" - Royal Victoria Hospital, Montreal, Canada by
McGill Library, on Flickr

Royal Victoria Hospital, Montreal, Canada. by
McGill Library, on Flickr

Montreal. Royal Victoria Hospital. by
McGill Library, on Flickr
https://www.researchgate.net/profile...his-aerial.ppm
https://en.mogaznews.com/content/upl...36e17e3e3b.jpg
https://lh3.googleusercontent.com/pr...DaI2rhPmEmh1go
https://lh3.googleusercontent.com/pr...Ty9JvZzOA5sfaq