We are planning a two weeks boat trip in Burgundy: Yonne (Migennes, Auxerre), Canal du Nivernais (Vermenton, Châtel-Censoir, Clamecy, Tannay, Corbigny, Baye, Decize) and Canal latéral à la Loire (Nevers, Argenvières, Sancerre, Châtillon-sur-Loire). Although we're tied to canals we will bring bicycles on boat so short trips of couple of kms from canals are something to think about. Also there is possibility to hire a taxi for longer distances. Kids are 7 and 11 and probably will have little patience for art museums and cathedrals. They probably would like medieval castles and caves - and of course any other "kids" activities like theme/water parks and so on..
The only thing I've managed to find so far along the route and which may be interesting for kids is Chantier Médieval de Guédelon which is a hour drive by taxi from Auxerre or half-hour from Neuvy-sur-Loire..
Oh, forgot to mention that we're planning the trip from Sep. 9th to Sep. 25th., so if anybody aware of festivals activities at those dates in this region - please share..Edited: 2:20 am, October 27, 2012