Château des Rochers-Sévigné lies just outside Vitré and is tied to Madame de Sévigné, whose 17th-century letters are a classic of French literature. The estate is more genteel than dramatic, with gardens and a small museum rather than fortress walls.
It is best for travellers with a car or a specific interest in French literary history. For most visitors, it is an extra after the old town rather than the main reason to come.