When people think of a zoo or animal park, they usually expect a sprawling park with open enclosures where elephants, lions, giraffes, and other—often large—mammals can be observed. The Haus des Meeres, located in the heart of Vienna’s 6th district (Mariahilf), is, however, the absolute opposite of a “normal” zoo. Housed in a former anti-aircraft tower from World War II, it combines a unique ecosystem with a turbulent history and what is arguably the world’s most unusual zoo architecture across 5,000 square meters.
From war memorial to vertical wilderness
Vienna’s Haus des Meeres is architecturally unique worldwide. Housed in a former anti-aircraft tower from 1944, the massive concrete structure bears witness to the dark history of World War II. Demolishing the colossus after the war was impossible: the walls are up to 3.5 meters thick —blasting it would have leveled the surrounding residential buildings in the densely populated Mariahilf district.
Thus began the gradual transformation into a zoo in 1957. In small stages, nature reclaimed the bunker: initially, only one level was provisionally used as an aquarium, before steady expansions transformed the tower into a “Vertical Zoo.” The architectural feature lies in the vertical use of the eleven floors. Since the building is a listed historic structure, highlights such as the glass tropical house were attached directly to the exterior facade. Today, state-of-the-art animal care and historic architecture merge across 5,000 m². With the addition of the glass extension in 2020, the building took on its current form—a place that now protects life rather than threatening it.
An ecosystem between the deep sea and the sky
At Haus des Meeres, a spectacular journey through our planet’s habitats awaits you— spanning eleven floors. The centerpiece of the “Vertical Zoo” is the massive shark tank, which spans two floors. With a capacity of 300,000 liters, it provides a majestic home for blacktip reef sharks and the famous sea turtle “Puppi.” Another technical masterpiece is the Atlantic Tunnel: Here, you walk through a glass tube in the middle of a 500,000-liter tank, while rays and nurse sharks glide right over your head.
In total, over 10,000 animals representing more than 600 different species can be discovered in the former anti-aircraft tower. On the upper floors, you leave the water behind and enter the Tropical House and the Crocodile Park. Here, the atmosphere is pure jungle, while white-headed sakis and colorful birds often dart past visitors just centimeters away. Those who prefer bizarre tiny creatures can admire the world’s longest leafcutter ant trail, which winds its way through transparent tubes across an impressive two floors. From venomous crust lizards to prehistoric Komodo dragons and delicate seahorses, the facility offers an enormous variety.
The crowning glory of this urban ecosystem is the observation deck on the eleventh floor. Up here, a breathtaking 360-degree view over the rooftops of Vienna turns the visit into an unforgettable experience between the deep sea and the sky.
📍Fritz-Grünbaum-Platz 1, 1060 Vienna 🕰️Monday – Sunday 9:00 AM – 8:00 PM
