Discover Vernon's rich medieval heritage on this compact walking tour through five centuries of history. Begin at the magnificent Notre-Dame Collegiate Church with its stunning 15th-century Gothic façade and exceptional 1610 organ, then admire the beautifully preserved 15th-century House of Times Past with its distinctive half-timbered architecture. Continue to the imposing Tower of Archives, a 22-meter cylindrical keep built by King Philip Augustus in 1196, before visiting the iconic Old Mill perched on medieval bridge piers – famously painted by Claude Monet in 1883. End at the Château des Tourelles, a 13th-century fortress with four distinctive turrets guarding the ancient Seine crossing. Important: The Tower of Archives is only open during European Heritage Days in September. All attractions can be viewed from the exterior year-round and are free to visit. Total walking distance is approximately 1 km, taking about 2.5 hours including visits.