The only vestige of an ancient medieval building, the Balhan tower in Château-Thierry, in Aisne, dates from the 15th century. Largely damaged during the First World War, it underwent a major restoration campaign in the course of the 20th century.
Listed as a Historic Monument, the Balhan tower has a square plan and extends over about thirty meters. Flanked by two watchtowers and surmounted by a bell tower, it also reveals a large spiral staircase inside. It was once part of a stately home transformed into a private mansion during the 15th century.
