• The castle: Castle Dourdan, completed in 1222 by Philippe Auguste, succeeded a wooden building dating back to Hugh Capet. Its regular plan is characteristic of the Philippian system. In Île-de-France, Dourdan is one of the only fortress of the thirteenth century which has retained much of its structures: the keep, towers, dry moats... From 1672, the castle was transformed into a prison by Philippe d'Orléans. Became county jail to the French Revolution, it houses prisoners until 1852. It was then purchased and donated to the family in 1864. Joseph Guyot Guyot spends his life to restore and renovate. The set is historical monument since 1964.
• Dungeon: Symbol of royal power, the dungeon is circular, at three levels. It is a remarkable example of military architecture, with beautiful vaults. It has a height of 26 meters. The top of the tower which included hoardings and a pepper-box roof, disappeared. All that remains is a terrace from which you can admire splendid views of the entire city and its surroundings Dourdan.
• The Castle Museum: In the courtyard is the municipal museum in a former eighteenth century salt warehouse built by the Marquis of Verteillac. A century later transformed into housing by the owner of the castle, Joseph Guyot, this home has retained much of its Neo-Gothic and eclectic decor. This museum label museum of France, home to high quality collections, testimonies Heritage Dourdan.

• Archaeological Pottery: Gallo-Roman and medieval.
• Model of the castle.
• Funds from the former Hotel Dieu Dourdan: pharmacy jars, furniture, old paintings including a Madonna and Child of the sixteenth century attributed to Coeck van Aelst.
• Prints, paintings, sculptures from the sixteenth to the twentieth century.