Biarritz' splashiest sea-themed attraction is part museum, part theme park and part educational centre. It takes a fun approach to learning about the sea in all its forms – attractions range from a chance to explore a marine lab to a simulated dive into the depths in a bathysphere. It's good fun, but probably of greater interest to older kids.
In July and August a free navette (shuttle bus) runs between Musée de la Mer and the Cité de l'Océan. Tickets can be booked online.