The 13th-century fortress of Château de Dourdan

The Château de Dourdan rises above the town of Dourdan in the Essonne region of France like a sentinel of the past. Built at the request of Philip Augustus in the 1220s to replace a wood structure, the castle features a geometric pattern and an isolated donjon. These elements were similar to those found at the castle of the Louvre. The principle of the isolated keep was also employed at Flint Castle in Wales and Yverdon Castle in Switzerland. The donjon itself measures approximately 30 meters in height and 13.6 meters in diameter, serving as the castle's primary defensive component.

The châtellenie of Dourdan was part of the Crown lands of France from the 10th century. The castle became the property of Jean de Berry in 1385 and was later besieged during the French Wars of Religion. Among some of the notable personages who resided in the castle were Philip IV of France's daughter-in-law, Joan II, Countess of Burgundy, detained there from 1314 to 1315 in relation to the Tour de Nesle affair, and La Hire, one of Joan of Arc's comrades-in-arms.

By the end of the 17th century, the Château de Dourdan was given to the Duke of Orléans who turned it into a prison. The donjon was used as a prison until 1852. Today, the castle houses a museum of local history.

Sources: Wikipedia, OpenStreetMap, Wikidata, Wikimedia Commons