A lot of us Calgary forumers have been itching for a supertall (our new tallest U/C the Foster designed 'Bow' only reaches 774'). There is one parking lot almost smack dab in the middle of our CBD, and can go over the 1000' height without violating the shadowing restrictions for our river pathway to the north, here is the site:
I believe the site is currently owned by Imperial Oil, and perhaps at some point they will out-do EnCana and their new tallest by going higher in this spot.