Oceanario de Lisboa (Lisbon Oceanarium), Lisbon (must see)

The primary attraction within Nations' Park ("Parque das Nações") is Europe's most extensive aquarium, housed in a structure resembling either an offshore drilling platform or a massive, modern seafaring vessel. This remarkable facility meticulously replicates four distinct underwater and shoreline environments, spanning from the Atlantic and Pacific to the Indian and Arctic oceans. Your exploration begins on the upper level, affording you the opportunity to observe surface-dwelling creatures representative of each climatic zone, including otters, puffins, penguins, and an assortment of sea birds.

Descending to the lower level, you embark on another circuit, this time encountering the mesmerizing world of underwater creatures. The centerpiece, which you'll repeatedly encounter and can view from various perspectives, is a vast and enchanting central tank teeming with an array of captivating fish, ranging from large to small. Notably, several sharks coexist harmoniously with bream in the softly illuminated waters of this tank.

Why You Should Visit:
To witness marine animals coexisting harmoniously, seemingly side by side, with none appearing threatened by the presence of others.
Should you happen to find a window without the company of school groups, the entire experience provides a sensation akin to deep-sea diving, all without requiring you to get wet.

Tips:
Purchasing your ticket online will allow you to bypass the queue. To steer clear of crowds or the commotion caused by energetic children, consider arriving close to the opening hours.
If you're seeking a spot to take a break and rest your legs for a while, don't miss the public hammocks located in the quaint park just before the entrance.
Outside the aquarium, you'll enjoy a splendid view of the Vasco da Gama bridge. Additionally, until 5 pm, you can take advantage of the cable cars, which offer exceptional vistas.