This fortress is what remains of a fortified castle built in the 15th century by Jean de Créquy, Knight of the Toison d'Or (Golden Fleece). It bears witness to the turbulent history around the regions of Hesdin and Thérouanne. The gardens of the 3-hectare park are designed in a Medieval style, with the addition of medicinal plants. You can visit the underground passageways and the former residence of the nobles. There is also an educational and entertaining permanent exhibition on the architecture of castles between the 9th and the 17th centuries.