3 days in Normandy in late August with 3DC

[LemonyPicket]

We are getting the ferry to Le Havre and have 3 nights to spend in the Normandy area before we drive further down to Brittany (Saint-Cast area). DH is a history geek but he has done the WW2 sites before with his dad and our 3DC are only 6, 4 and 1 so this won't really be a history/museum-y trip. However in Brittany we are staying somewhere semi-rural near the coast for a week so for this first leg we would like a bit of culture and interest before we veg out on the beach. I know the weather in Normandy can be hit and miss. We would prefer to stay in an AirBnB rather than hotel or Eurocamp. Thanks for any tips!

We’ve stayed in Caen a few times en route south. It’s a good base for lots of day trips with small kids:
Festyland
Bayeux tapesty musuem
Zoo du Jurques
Bayeux Aventure
Clecy Gliss and La Monde Miniature at Clecy

Mont St Michel is amazing. Yes it's very busy but it's absolutely worth it. Bayeux tapestry museum is also very interesting and Bayeux is a lovely small town.

Edited to say I see your dc are still pretty young so may not appreciate the tapestry!