1970s, Canadian National Exhibition
The CNE, or more commonly known as simply 'The Ex' has been around since 1879.
This postcard shows a night view of the midway with the Shell Oil Tower rising high behind the Flyer roller coaster. Both were built in the mid 1950s but unfortunately demolished in 1982 and 1995 respectively.
The CNE runs for 18 days until Labour Day, which this year is Sept 4th, 2017
(see also here for an older version of the Shell Oil Tower)