The Lisbon Oceanarium is one of the city's top attractions and among the largest indoor aquariums in Europe. Located in Parque das Nações, it features a vast central tank with thousands of marine species, including sharks, rays, and tuna, surrounded by habitats representing the Atlantic, Pacific, Indian, and Antarctic Oceans.

Visitors can also see sea otters, penguins, jellyfish, and rotating exhibitions focused on ocean conservation and biodiversity. Known for its striking architecture and immersive design, the Oceanarium offers an engaging experience that combines education, environmental awareness, and entertainment.