vienna.info - You can enjoy this sensational view of Vienna at the newly opened café "oceansky" on top of the Haus des Meeres Zoo. And don't miss to visit the new aquarium
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Index to List of Zoos and Aquariums of the World - 2017 - International Zoo Yearbook - Wiley Online Library
Haus des Meeres: 1000 Awesome Stuff To See - Vienna 101