By the late 1970s, DON MILLS CENTRE has been enclosed and climate-controlled. Its South Wing was fully realized in the mid-1960s (shown in dark gray). The Eaton's store was also enlarged. As part of the 1970s enclosing renovation, open areas were filled with new store space (shown in light gray). The mall now encompasses over 400,000 leasable square feet.

A circa-1980 view of the new interior mall of DON MILLS CENTRE.
Photo from / The Toronto Star

Since 1968, DON MILLS CENTRE had been owned by the Fairview / Cadillac Fairview Corporation. Their most prestigious Metro Toronto property, FAIRVIEW MALL, opened in 1970. Although both complexes were owned by the same company, FAIRVIEW MALL was a major rival of DON MILLS CENTRE.
Photo from Wikipedia / "GTD Aquitaine"