Walk the loop of the River Ill to hit the medieval core without the tour groups. Start at the Cathedral for the astronomical clock show, then ditch the main square for the narrow alleys of Petite France. Most spots close early, so aim for a sunset stroll when the water reflections peak. Skip the pricey river cruises; you'll see more on foot in two hours. Grab a tarte flambée from a side-street bakery and keep moving.
