Château de Blain, also called Château de la Groulais, is a medieval fortress dating to the 13th century and remodeled in the 16th, located in Loire-Atlantique. It features 12 towers spanning four hectares and sits beside the Canal de Nantes à Brest, forming part of Brittany's historic frontier defenses. The castle houses a fresco center and ancient printshop, serving as a monument historique since 1977. Marie Bonaparte, a wealthy descendant of Napoleon I, owned it from 1918 to 1950 and undertook its restoration.
