The Haus des Meeres is a major public aquarium and zoo located in Vienna. It is housed in a former flak tower from World War II, a structure that has been repurposed for this modern use. The facility features an extensive collection of marine and terrestrial life, with exhibits spanning multiple floors. Visitors can observe a wide variety of aquatic species in large tanks, including sharks, tropical fish, and coral reef ecosystems. Beyond its aquatic focus, the institution also maintains a significant collection of reptiles, amphibians, and insects. A notable feature is a free-flight hall for birds and a dedicated area for monkeys. The rooftop offers a viewing platform with panoramic views of the city. The aquarium plays a role in species conservation and educational outreach, providing information on biodiversity and ecological conservation. It has undergone several expansions to increase its exhibition space and enhance the visitor experience.