We came here on our boat last summer. The locals refer to it as Donjon de Vic-sur-Aisne. The first castle was built in the 8th century. It was part of the defense that stopped the Normans in the 9th century. The keep was built in stone in the 12th century to a height of 25 meters with walls two meters thick. The castle was badly damaged, the battlements and parapets dismantled and the towers destroyed. An abbot rebuilt in the 17th century, adding a chateau with a mansard roof adjacent. The castle was French headquarters in WWI. The front was just a few kilometers.
Here is my post from our visit https://garyjkirkpatrick.com/lots-of-locks-but-no-bagels/
