Spend time in St-Malo, which is far from just a ferry port. A combination of picturesque seaside resort, ancient walled pirates’ city and great shopping spot, it has a brilliant aquarium, the Grand Aquarium, especially good for younger kids.
Stop off at the gritty naval port of Brest, for a boat trip around its amazing Rade or natural bay, and a day (you’ll need it) at Océanopolis, one of the world’s greatest sea-life centres.
Explore the Côte de Granit Rose, a stretch of coast full of pinkish rocks carved by the elements into weird and wonderful shapes, occupying fabulous turquoise bays. Family holiday resorts here include Perros-Guirec, and you can spend time trying to recognize the site of the nameless village in which the Astérix comic books are set.
Stray into the inland valley of Huelgoat, with its strangely shaped rocks and even stranger legends, some of them related to King Arthur, Merlin et al. Even a child can move the 100-tonne Roche Tremblante if they touch it in the right place, while some claim to see fairies bathing by moonlight in the Mare aux Fées.
Venture over to the wild, windswept island of Ouessant, to see the most powerful lighthouse on Earth, the world’s only lighthouse museum and some unique dwarf black sheep.
Wonder at Carnac, the most important prehistoric site in Europe, with as many as 3000 menhirs (tall upright stones) that have been here longer than the pyramids in Egypt and are believed to have formed a lunar observatory. The majority now have restricted access, but there’s a good, child-friendly prehistory museum, Musée de Carnac, that puts them in context. They are close to the lovely seaside resort of Carnac-Plage, too.
Head for the hip regional capital Rennes, to learn about Brittany's history at the Musée de Bretagne and about science at the adjoining Espace des Sciences with its planetarium and ‘Merlin’s Laboratory’ children’s discovery zone.
Nip over the border into Normandy, to see the glorious UNESCO-listed Mont-St-Michel. Chug out aboard a tractor-drawn cart into its spectacular bay of sandflats to see mussels growing on bouchots (sticks).