Rivière-du-Loup is a Bas-Saint-Laurent town on the south shore of the St. Lawrence, useful on the Quebec-to-Maritimes road but better than a simple overnight stop. The river drops through town in a real waterfall, the old centre has enough stone and brick to reward a wander, and the ferry turns the broad St. Lawrence into part of the day.
The best visit stays close to water. Walk Parc des Chutes, cross to Charlevoix on the Rivière-du-Loup-Saint-Siméon ferry, or take the seasonal boat out toward Île aux Lièvres for trails, birds, and a quieter river landscape.
The town also has a good regional museum and a lively Rue Lafontaine, so it works as more than a transport junction. If you are already moving along the St. Lawrence, Rivière-du-Loup is worth slowing down for.