Nantes is a vibrant city known for its rich history and unique attractions like the Château des Ducs de Bretagne, a stunning historic castle, and the Isle of Versailles, a serene Japanese-style garden perfect for relaxing walks. The city also boasts the beautiful Passage Pommeraye, a 19th-century shopping arcade with impressive architecture. With about 7 hours to explore, you can enjoy these free or low-cost highlights, soak in the local culture, and savor the lively atmosphere of the Bouffay district.