I am an engineer, so anything Science is great for me...
This museum has great displays on the Solar System, the planets, and many other celestial objects. Lots of great reading about what lies above in the Sky.
It is located in Laval, north of Montreal, there's a free private lot.
If you are interested there are several other side shows that you can buy for an additional price, but I decided just to stick with the Main Show. Space exploration, Space Camp, Virtual Missions, are just some of the examples of fun things you can do for an additional fee.