Stopping in to see the Notre Dame is a must in Montreal. We arrived slightly before 10am on a Saturday morning (Easter weekend) and found a bit of a line, so we jumped right in. The line moved pretty quickly however, and I appreciated the fact they had an employee who walked along the line giving out info about prices, currency, CASH ONLY etc. When we left at closer to 11am the line was practically double what we waited in, so COME EARLY!
$6pp for adults which was more than fair. I've seen my fair share of amazing churches/mosques/temples around the world, and the Notre Dame didn't disappoint. Beautifully painted ceilings with great stained-glass sky lights, the interior will definitely take your breath away.