Umm, of course Princes island and St Patrick’s Island are downtown, and accessible freely, by foot. So no, I wouldn’t have to include the Toronto islands, as they’re accessible only by a 15 minute boat ride which one must pay for. Not even remotely comparable.
Following list includes parks with at least half a city block of greenspace.
15 - 20 min *walk* (not boat ride) from Calgary Tower:
Princes Island
St Patrick’s Island
RiverWalk
Beaulieu Gardens
Lindsey Park
Central Memorial Park
Harley Hotchkiss Gardens
McDougall Centre
West Eau Claire Park
Olympic Plaza (?)
Haultain Park
Barb Scott Park
Century Gardens
20 - 25 minutes walk:
Millennium Park
Scotsman Hill
Crescent Heights Lookout
25 - 35 min (Toronto distances, and about the same as the islands even by boat not including wait times at the terminal):
Thomson Family Park
Roxboro Cliffs
Elbow Island Park
Evamy Ridge
I’m sure I’m forgetting some. Point being, you can’t go three blocks in any direction in Calgary’s 6 downtown neighbourhoods, or the entire inner city for that matter, without hitting a greenspace.
If you were talking about Toronto's many fully paved concrete/brick plazas… honey those are plazas, not greenspace, which was what was being discussed. Yes those are nicer than ours for what they are, because we choose greenery over stone.