Definitely the 70s. 1980 was about when Principal Plaza was under construction followed by IPL the Manulife.It took me a while to figure out where that was. Lots of high rise buildings under construction, this must have been sometime in the 1970's
I also recognize the old Cecil Hotel at the corner of the block - now long gone, the construction in front where the park now is and the parking lots, which are now nicely filled with tall buildings. IMO much better now, but is anything actually still left on this block?
Too bad we lost some of those trees! Those were nice.