La Couronne, on the Place du Vieux-Marché, claims to be the oldest inn in France — founded, the sign says, in 1345 — and is one of those touristy-but-genuinely-good Norman restaurants that earns its reputation. The menu is reliably classical: duck à la Rouennaise, sole meunière, tarte Tatin, the kind of dishes that have been on the carte since long before anyone alive can remember.
Lunchtime set menus are the value option; à la carte gets steep. Worth a visit at least once for the dining rooms — small, low-ceilinged, half-timbered — even if the food is no longer Rouen's most cutting-edge.