Donjon de Châteaumur is a dungeon built in the 12th century. An enclosure, either made of wood or stone, may have enclosed the keep in an almost circular area. What is certain is that, during this time, the keep was designed as an independent fortress, with a door located on the second floor and protected by a drawbridge that fit into the wall and the doorframe. The interior was divided into two by a partition wall for stability, and it had four levels: a basement and three floors with wooden floors. The ground floor stored provisions, the first floor housed the lord's residence (along with the drawbridge), featuring fireplaces and latrines, and the second floor likely had a guard room with access to the battlements. This top floor was accessible from the first floor via a spiral staircase embedded in the southeast buttress.
Perhaps in the 14th century, during the Hundred Years' War, an enclosure was added. Some parts of it are still visible because the houses around the keep's square are built against it, and there remains a fortified gate for carts. Another larger enclosure surely existed; one can see evidence, for example, just above the chapel's calvary. This could have been a wall or a palisade.
References:The Château du Lude is one of the many great châteaux of the Loire Valley in France. Le Lude is the most northerly château of the Loire Valley and one of the last important historic castles in France, still inhabited by the same family for the last 260 years. The château is testimony to four centuries of French architecture, as a stronghold transformed into an elegant house during the Renaissance and the 18th century. The monument is located in the valley of Le Loir. Its gardens have evolved throughout the centuries.