Considering the Kyriad Hotel de la Plage in Arcachon?
A VT member wrote the following comment about visiting Arcachon:
Banc d'Arguin by bijo69
The Banc d'Arguin is a sand bank located right in the entrance of the Bassin d'Arcachon. It's a nature reserve and a nesting and hiberanation place for many birds.
During the summer months you've got a ferry connection from the Dune du Pilat to the Banc d'Arguin, at other times you'll need your own boat.