La Rochelle is famous for its arcades — long covered walkways running down both sides of the main shopping streets, built into the ground floors of the buildings to shelter merchants and customers from the Atlantic weather. The Rue des Merciers, the Rue du Palais, and the Rue Chaudrier are the best stretches: independent shops, cafés with tables under the arches, and the limestone facades of three centuries of merchant houses above.
This is the part of La Rochelle to wander without a plan. Look up at the carved stonework on the older buildings — you will see Huguenot symbols on some, marine motifs on others. The independent retail still hangs on here in a way that has vanished from most French city centres: bookshops, a couple of decent record shops, makers of marrons glacés. Saturday mornings are busy in a good way.