Standing on a natural spur overlooking the Suize valley, the keep is the only vestige of the castle of the Counts of Champagne, the birthplace of the town.
At 19 m high, this square tower has retained its medieval appearance, with walls varying in thickness from 2.60 m at the base to 1.50 m at the top.
The rustication of the stones in the lower section indicates a late date: the second half of the 12th century.
Originally a defensive structure built by the lord of the castle, once topped by a hoarding, it was later used as a prison. Inscriptions engraved on the walls date back to this period.
The Chaumont Museum of Art and History is located at its foot.
Listed in the supplementary inventory of historic monuments.
Donjon des Comtes de Chaumont
