This is fun, the display here might actually be the best I’ve seen so far for finding “iNatting hotspots”.* At very well iNatted places you can actually see where the trails are because the observations are so much denser there.
In southern Ontario there aren’t really tourist-dominated areas, Niagara Falls stands out a little which makes sense. I’m a bit surprised up much more touristed Montreal is than any Ontario cities. Pelee, Long Point, and Algonquin are all major naturalist destinations which essentially nobody lives at, but many naturalists will go to them every year which I guess makes them count as locals.
(*I’m thinking now that a really cool map would be one similar to this but that colours the observations on a scale based on how many species have been observed within e.g. a 1 km radius of the observation.)