The CN Tower is fantastic most certainly. However be forewarned the area surrounding the tower (especially on the southside) is undergoing heavy construction. What is now a big hole will eventually be home to a Ripley's Believe-it-or-Not attraction.
Other places to visit in the GTA could be:
--> Union Station (where the ViaRail trains stop) has great architecture.
--> Harbourfront (along the shores of Lake Ontario) is very beautiful.
--> Though I have never been, I have heard the Royal Ontario Museum is fantastic.
--> If you are into malls, the Eaton Centre is Toronto's flagship and is located downtown.
Toronto's downtown is quite large with towering skyscrapers. Streets are laid largely in grid-form, so way-finding is somewhat straightforward. Be sure to grab a detailed map at your first opportunity (also available in the website linked below). If you have Google Earth or use Google Maps, I would encourage you to make use of the Street View feature to get aquainted as to what the buildings look like from the perspective of the streets and to determine where things are in relation to other things.
If you haven't done so already, consult the official Toronto tourism page (click here) to help you focus on what you might want to do. To get a map, hover over the "Explore" tab and then click "Guides & Maps."
Toronto is a big cosmopolitan city with tons to do. I have been to Toronto for a grand total of 9 nights over three years (most recently early March of this year) for conventions.
Hope I have helped and please enjoy your GTA experience
~CGKings317
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I LOVE volcanoes and aviation but the two of them DON'T get along. NEVER fly and aircraft into an ash cloud-- just ask KLM867 & PH-BFC