Toronto is a city that can easily be done in about 3 days, especially in winter when outdoor options are limited. The CN Tower is a must-see on any trip to Toronto, regardless of season. A couple of tips here: if you're going to the Royal Ontario Museum, Casa Loma, Ontario Science Center as well, you might strongly want to consider the City Pass...it can save you over $100USD if you're a family of 4.
Anyway, the tower is very cool. The SkyPod (highest accessible point) is closed for renovations right now (end of January 2014), but the general admission to the top point that is accessible doesn't disappoint. It's pricey, but worth it, considering most attractions cost the same and dont have what this one does ($99CAD for a family of 4): The elevator ride alone is worth it. I'm a New Yorker and remember taking the elevator to the top of the Twin Towers...this feels similar to that, except a portion of the elevator is see-through...can you imagine? VERY COOL! My kids, 4 and 7, were amazed the entire time. We had dessert and a cocktail at the Horizons restaurant (with a view of the city), went a couple of flights down to check out the glass floor (yes, you are literally walking on a see-through floor from over 1,000 feet up!) and then stopped at the film and ride floor (my daughter was under 42" so she couldn't ride, but it's included in the Gen Adm price anyway so my husband and son went). The gift shop doesn't have too many offerings (maybe this is a good thing!) and there's an arcade for bigger kids. In warmer times of year, there's an Edgewalk ride (not really a ride, but people pay money to hang off the side of the building!).
I would do this again, and definitely recommend it to a first-timer.
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