The largest oceanarium in Europe, and the second-largest in the world, has seven sections devoted to different ecological zones. The building was designed by Félix Candela to resemble a water lily. Highlights include a dolphinarium, a walk-through shark tunnel, a shark tank (open for public diving), and spherical bird aviary. There are several restaurants on-site, and with so many attractions it’s easy to make this into an all-day affair.