The Oceanarium - The underwater world
Lisbon's Oceanarium is one of the world's largest aquariums. Designed by American architect Peter Chermeyeff, it rises from the river and is reached by a footbridge.
It is a deep-sea diving experience without any of the risks, with about 25,000 fish, seabirds, and mammals in an enormous central tank that is the size of four Olympic-sized swimming pools.
Visitors can look into it from different levels for close-ups of the various creatures, including different species of sharks. But it's the design rather than the size that makes it outstanding.
It is the first aquarium ever to incorporate world ocean habitats within a single environment, with impressive recreations of various ocean ecosystems -- the Antarctic tank containing penguins, and the Pacific tank with otters playing in rock pools. They are all separated from the main tank by invisible acrylic walls, giving the impression that all the creatures are swimming in the same space.
There are also high-tech multilingual interactive displays explaining the development of ocean life.
as well as a variety of performances at the rotating central bar, 
The Portugal Pavilion is a striking building designed by Portugal's Pritzker Award-winning architect Alvaro Siza Vieira.
One of the most stunning modern sights in Lisbon is Oriente Station. It was built by master architect Santiago Calatrava with a roof of glass and steel made to look like a row of trees.
From the Oceanarium, a cable car takes visitors to the futuristic Vasco da Gama Tower. It is named after one of Portugal's greatest explorers and was opened in 1998, on the 500th anniversary of his voyage to India.
