The Grande Rue is the architectural centrepiece of Richelieu — the main axis of the planned town, lined on both sides with identical 17th-century stone townhouses. Mansard roofs, uniform façades, matching proportions: the effect is more like a stage set than a living street, though people do live here. The repetition, which might seem monotonous, becomes genuinely striking when you understand that every house was built to the same specification at the same time, in the 1630s, and has remained essentially unchanged since.
At each end of the town, the original gateways survive: the Porte de Châtellerault to the south and the Porte du Chinon to the north. Both are intact 17th-century triumphal-style arches, and walking through them frames the street in a way that makes the Cardinal's urban ambitions legible.