History
The castle is first mentioned in the late 11th century. Its first known lord, Bernard de Montbard, was the grandfather of Saint Bernard of Clairvaux through his daughter. In 1189 Duke Hugues III of Burgundy acquired Montbard in exchange for Époisses. The dukes turned it into a strong fortress in the 13th and 14th centuries, and the Valois dukes often stayed here in the 15th century.
Buffon's father bought the local lordship in 1718. Between 1733 and 1742 Buffon took over the castle, cleared the ruined buildings and filled the ramparts with earth to create terraces. He kept the Tour de l'Aubespin, the old keep, and the church, and lowered the Tour Saint-Louis by one storey. In a small study on the ramparts he wrote much of his Histoire naturelle. The town bought the abandoned estate in 1870 and made it a public park.
Architecture
The Tour de l'Aubespin is a tall polygonal keep with four vaulted floors and machicolations, a rare survivor of the ducal castle. The Tour Saint-Louis, cut down by Buffon, held his library. Around them, fourteen terraces in the French and Italian manner step down the hill, with trees, flowers and an orangery. Buffon's cabinet de travail, his simple study, still stands on the western rampart.