
Château de Franchimont is a medieval fortress in Theux, Belgium, originally one of twelve defensive residences built by the Prince-Bishop of Liège starting in the 11th–12th century to protect the eastern territory of the principality. Though largely demolished during the French Revolution, substantial ruins remain demonstrating how military architecture evolved with the introduction of gunpowder artillery, making it an exceptional archaeological site. Preserved features include a keep, casemates, fortifications, a squirrel wheel mechanism, bread oven, and guard room. The castle welcomes individuals, families, and groups; visits lasting 1.5–2 hours are supported by audio guides (€2) in four languages, while guided tours and animations lasting 2.5–3 hours are available by reservation. Children under 4 enter free; combined entry plus guided tour costs €9 for adults.