You can literally immerse yourself in marine life while walking through a 260 foot sea tunnel at the Barcelona Aquarium. Since opening at Port Vell in 1995, L’aquàrium has delighted 1.5 million visitors a year with 450 species of fish in over 20 aquariums. The centerpiece is the Oceanarium. Swimming in the one million gallons of water is a stunning array of aquatic life including sharks and stingrays. Kids are especially fascinated when staff feed the penguins and sharks.