In Paris there is the Eiffel tower, in Montreal there is the bridge Jacques Cartier, originally opened in 1930 and named for the first four years the Harbour bridge. If you love large steel structures that look like giant lego, then this bridge is for you. It connects the island of Montreal to Longeuil with a possible exit and/or entrance on St-Hélène Island. And if you can take it by car you can as well cross it by bike and on foot! No need to say that the view is amazing and the wind situation real.
By night the bridge is often lit, but for me the best way to experience is to actually walk on it or cycle on it of course. You don’t have to do it all along its length, but a part of it is enough, let’s say from the subway station Papineau to the island and then return by subway from the island by the Jean-Drapeau station. Don’t rush it either: once you have left the sidewalk you are actually almost facing the entrance of La Ronde amusement park where more metal structures of various shapes are waiting for you.