Monet's House and Garden (Giverny) - Stand on the Japanese bridge overlooking the waterlily pond and kids can imagine themselves into a Monet painting. Enjoy wandering through the weeping willows around the water garden and among the exuberant flowers in the main garden.
Parc Asterix (Plailly) - If your kids read the Asterix comic books, this theme park is a must. Plenty of water fun, exciting rides, shows and Asterix characters. The park is open April to September.
Air and Space Museum (Le Bourget) - At the end of his solo flight across the Atlantic, Charles Lindbergh landed at Le Bourget airport. The Air and Space Museum at Le Bourget (Musee de l'Air et de l'Espace) has a particularly good collection of hot air balloons, early planes in aviation history including the Bleriot XI, as well as planes from World War II and a prototype of the Concorde.