How long in Le Touquet with a 3 year old?

[SueDNim]

We are planning a trip to Le Touquet in September. We will probably spend a couple of days on the beach and around Le Touquet and a day in Boulogne to go to the aquarium. What else is there in the area that might be good for a 3 yo? We don't really want to travel more than about 1 hour to get to things. Can anyone recommend what there is to do in the area and how long to stay for?

Some nice beaches all along that stretch of coast , Bagatelle theme park, train journeys and wildlife around the Somme estuary and cycle paths through the forest.