Built for the 2008 Expo, Zaragoza’s aquarium focuses on five of the world’s great rivers from the Amazon to – closer to home – the Ebro (the facility sits on its banks). There are plenty of fish, reptiles and other animals to see, plus explanatory boards in Spanish and English. A couple of kilometres from the city centre on the old Expo site, it rarely gets crowded.
The aquarium is on the route of the Bus Turístico; you can also take a northbound tram to the Clara Campoamor stop then walk 800m west through residential areas.