The Musee Stewart is small museum nestled on the island of Jean-Drapeau next to the La Ronda amusement park. The museum contains manly different levels of exhibits beginning on the third floor. You can take the elevator or you can take the beautiful glass and mirror staircase to the top to begin.
The collections range from Montreal and Quebec history, a board game history level where you can actually interact and play the games on display, and a level they call Curiousity where each exhibit is hidden behind different colored doors. This was probably my favorite. It was just such an interesting exhibit.
To go through the entire exhibit doesn't take much time so it's easily something that can be added to the itinerary while visiting the island.
I would highly recommend Musee Stewart if you plan to visit this area.