The Château de Dourdan was built at the request of Philip Augustus in the 1220s in the place of a wood structure. The castle became the property of Jean de Berry in 1385. It was 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.
At the end of the 17th century, the Château de Dourdan was given to the Duke of Orléans who turned it into prison. The donjon was used as a prison until 1852. It now houses a museum of local history.
The fortification is characteristic of the military architecture of this period. It is built on a square pattern, with towers at three of the corners and an isolated donjon at the fourth. The walls are punctuated by towers in the middle of each side, and two, on the east side, flank the gatehouse. A deep stone-lined dry moat follows the outline of the castle.
The donjon, the major defensive component of the castle, measures approximately 30 metres in height and 13.6 metres in diameter. It is the typical of the donjons being built by King Philip II Augustus of France at this time, like at Rouen and other French nobility throughout the 13th century.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.