From the town hall of Roinville, going up to the plateau via rue des Vignes, you should not miss the fortified farm of Châteaupers, a former fortified stronghold built in the 14th century, and its square tower. A dungeon which served as a watchtower in the Middle Ages: the watchman sounded his horn when he saw looters coming from the Orge valley, and the inhabitants ran to take refuge inside. The moat, partially filled in, and the drawbridge have disappeared, but Châteaupers has retained its original shape (a quadrilateral) and its medieval spirit. In the 16th century, the farm was brought as a dowry to the lord of Marais, by the daughter of the castellans of Villeconin. A tapestry, kept at the Cluny Museum, and a pencil portrait kept at the Cabinet des Estampes represent her. It is under the name of Lady of Chateaupers that she is designated in the collection of pencil portraits of the National Library. We can now discover the farm from the inside: the stately home, restored according to the rules of the art, has recently been transformed into a rural gîte. The opportunity to follow in the footsteps of Rachel de Cochefilet, the most illustrious mistress of these places, since she was the wife of a certain Sully, minister of Henri IV.