Tacot Des Lacs near Grez Sur Loing
If the kids like trains then you are in luck. Halfway between Grez Sur Loing and Montcourt Fromonville, beside the Etang de la Clarette, a small train museum called Tacot des Lacs. With over fifty trains, trams, carriages and traction engines and including a steam train that runs on its own line, it is a train lovers paradise.
For more information you can find them on the web and Facebook.