Located in Vieux-Montreal area, the Basilique Notre-Dame de Montreal (Notre-Dame Basilica of Montreal) should definitely not be missed.
Across the street from the Place d'Armes square, it is hard to miss the imposing structure, which was built in the Gothic Revival style in the 1820's. There were things that were added later on, like the pulpit in the 1870's. The church art is just amazing to look at, with the statues of the saints on each side at the altar.
There is a smaller, separate chapel in the back, past the main altar. It is called the Chapelle of Notre-Dame du Sacre-Coeur (Chapel of the Sacred Heart). With more light in the room, it does look brighter. Built in 1889, and opening 2 years later, this one was mainly used for weddings. The highlight is the wooden altarpiece, which is just amazing to look at.
You can see the place on a guided tour, either in English or French. Check the web site for exact times, and different types of tours, which are not the same costs. I did not go on the guided tours, so I can't really comment on them. Or simply, pick a brochure near the entrance, which shares some of the highlights of the place. Either way, this place is definitely worth visiting.
More info on the basilica and the different guided tours here... http://www.basiliquenddm.org/en/visits/discover.aspx
This review is the subjective opinion of a TravelPod member and not of TravelPod.com.