In May, I will be in both Toronto and Detroit for a few days. Benjamin will be with me, so keep in mind that I have a 3-year-old when making suggestions of things to do.

I'm looking for advice on interesting things to see/do in the area. Obviously Niagara Falls is one (80 miles from Toronto, and I was there 10 years ago). But I know very little about what there is to see in Toronto and Detroit, aside from knowing names of surrounding cities in each metro area.

Anything you could suggest would be helpful.

I will be driving between the two, btw. Yes, I realize they're like 230 miles apart.