I’ve seen this pic of this castle a lot and I wonder if anyone know if the castle is real (or has been destroyed) or if it’s just a fake castle. Hope I find a answer here and good day.
Nowadays, it is in ruins, but the castle depicted in the Book of Hours of the Duke of Berry was the castle of Méhun-sur-Yévre.
Source: Cazelles, Raymond, Les très riches heures du duc de Berry, La Renaissance du Livre, 2001, page 86.
Thats not Méhun-sur-Yévre. Its Paris. To be exact its the royal palace on the Ile de la Cite. You can clearly see the Sainte-Chappelle on the right hand side of the image. Méhun-sur-Yévre appears elsewhere in the Tres Riches Heures on folio 161v to be precise whereas the image given by the OP is part of the Image for the month of June.