This weekend is Doors Open, always a neat opportunity to see what's inside some of Toronto's historical buildings. In case, say, you've had a hankering to go to the Don Jail.
I haven't done a hard count to compare, but it looks like venues north of, say, St. Clair are a bit thinner on the ground this year. Still, worth a subway trip to investigate a few places.
The Star has some articles and handy maps here.