We can suggest a few places...
Jouarre.
Cheese dairy Ganot
http://www.fermes-brie.fr/
Abbey with its crypt
HTTP://TOURISMEPAYSFERTOIS.FR/
Château-Thierry
Old Castle, Jean de la Fontaine Museum and Hôtel-Dieu Museum :
Meaux
Museum about the First World War
http://www.museedelagrandeguerre.eu/
Belleau
American cemetery Aisne Marne in Belleau Wood
HTTP://WWW.MUSEE-MEMOIRE-SOUVENIR-BELLEAU.COM
Condé en brie
Condé Princes castle