Located in the old harbor, the Barcelona Aquarium is the world’s most important marine leisure and education center dedicated to Mediterranean undersea life. The aquarium boasts 66 Mediterranean and tropical tanks which are home to 11,000 animals from some 450 different species. The most spectacular of all displays is the Oceanarium. The Oceanarium is a transparent, 80-meter-long tunnel that allows you to walk among sharks, gilt heads, morays, ocean sunfish, and many more species as they swim around you. The aquarium also has an interactive kids section and play area where children are taught the importance of water in the development of our planet and can discover the underwater world by using their five senses.