Haus des Meeres is Austria’s largest aquarium and it also just might be the world’s most unique. It’s housed in a WW2 anti-aircraft flak tower that stretches up 11 stories. Stripped of weapons of war - it's now full of weird and wonderful wild animals. In addition to the many underwater creatures, you’ll find monkeys, birds, bats, crocodiles, salamanders, and many more.The aquarium tanks are huge and you can get lost in the moment as you watch schools of colorful fish swim by. The sea turtles are particularly charming - you’ll see them on land, lumbering towards a bowl of lettuce and they might remind you of a determined and enthusiastic great-grandparent. But when they take to the water you’ll see the grace that they possess.You’ll find plenty of sharks here. The hammerheads have an exclusive spot on the 10th floor, while there is also a separate, gigantic shark pool spread over two floors and measuring 300,000 liters. It has a variety of sharks, and they share it harmoniously with many other species of fish. If this isn’t enough to convince you that sharks aren’t the bloodthirsty beasts we fear (thanks Steven Spielberg), you can also catch zookeepers diving with them at various times during the week.Above sea level you’ll discover plenty of other animals to fascinate you. There are cute and playful monkeys, and creepy/fuzzy tarantulas! There’s even a crocodile park and distinct areas like the Amazonian Rainforest and Tropic House.The more than 10,000 animals they have here are spread out over ten floors, which are delightful diversions for the whole family. The cherry on top of it all is the café on the rooftop terrace. Enjoy a meal as you soak up some of the best views of this elegant imperial city.