I would definitely recommend checking out the Notre-dame when visiting Montreal. It is absolutely breathtaking. We went through a walking tour of the city and one of the spots was this beautiful church.
We also ended up walking past it at night, and it's just as impressive. I would recommend coming at night for sure. The night time view of the church from the plaza was amazing. the illuminating church with blue hues were so pretty. It was nice just to sit and take in all the beauty of the Notre-dame de Montreal. The plaza had lovely live music playing and families strolling with kids dancing. It was very picturesque.
So if you get a chance...I would recommend visiting!