Much of the castle's final appearance is due to the Marquis' tastes. He brought to Condé, the talents of the Italian architect Servandoni, a master of the "deception" style, and one of the architects of the Palazzo Farnese in Rome. He shut down the southern aisle, to allow the sun to penetrate into the rooms, and gave a symmetrical appearance to the other aisle. To achieve this, he was obliged to paint false windows in the medieval part of the Castle, the walls being 2 meters thick. For the interior decoration, he invited fashionable painters of the time - Lemoyne, his disciple Boucher, Watteau and his disciple Lancret, and last but not least, Jean-Baptiste Oudry.