At the Lisbon Oceanarium, you can see a huge main tank filled with a variety of marine animals. You can walk through a tunnel to see sharks, rays, and other sea creatures up close. The main exhibit is a massive 1,000 m2 tank that holds 100 species from around the world. The exhibit has large acrylic windows that provide panoramic views, including a rare sighting of the amazing sunfish, largest bony fish in the world.