Haus des Meeres, Vienna

Haus des Meeres is a public aquarium and zoo housed inside a former wartime flak tower in Esterházypark. Its tanks and enclosures now cover more than 8,000 square metres and contain over 10,000 animals, with a strong focus on Mediterranean life and tropical fresh- and saltwater habitats. You can encounter piranhas, sea turtles and coral among the aquatic displays, alongside reptiles and a tropical house where birds, fruit bats and marmosets move without cages or glass separating them from visitors.

The most unusual part of the building is the Atlantic Tunnel: a glass passage, suspended within an aquarium holding 520 cubic metres of salt water, lets you experience the tank from inside. The passage stretches for almost 15 metres and weighs more than 15 tonnes. This aquarium began with a clear ambition: in 1957, its founding society set out to create Austria’s first seawater aquarium in the former tower. From the ninth to the tenth floor, a small museum explains the tower’s wartime history, so the animals and the building’s difficult past remain part of the same visit.