Located at Parque da Nações, the Oceanarium is probably one of the biggest aquariums in Europe now. The main tank is very impressive for its huge size and one can see views of it from many different levels. About 100 species from around the world are kept in this tank, including sharks, rays, tuna, barracudas, groupers, and moray eels. One of the main attractions is a large sunfish. Four different habitats from around the world is a feature of this aquarium. Inside the building of the Oceanarium, it is a bit dark, but one just follows the arrows to see everything. The explanations are very educational and seeing this huge aquarium is very enjoyable for all ages.