Toronto starting to create a real skyline as seen in this photo circa 1971. Here we have the Sheraton Centre, York Centre and Commerce Court West all under construction at the same time. Commerce Court was the tallest building in Canada from 1972-1976.

And look at how dirty the Royal York Hotel was. All those years of dirty trains rolling by took their toll. But at least you could still see it from the lake unlike today. 

Toronto's Skyline, circa 1971,