Entrance Tunneling Adit Old Mining Break room Timbering Horse Stable Blue Lake Barbara Airplane Model Museum Barbara Adit Incline Ramp Shaft tower Festival Room

Seegrotte history

A stupendous natural phenomenon is responsible for the fact that southern Lower Austria is harbouring one of the most spectacular natural monuments of the world today: the "SEEGROTTE" in Hinterbrühl.

In 1912 an underground blasting operation in the gypsum mine "Hinterbrühl" went awry and caused 20 million litres of water to gush forth from behind the rock. The lower level galleries and adits of the mine were flooded, creating the largest subterranean lake in Europe. As a consequence the mine remained closed for years until an international team of cave explorers discovered the unique natural spectacle in the 1930´s.

With great enthusiasm they opened this curiosity to the general public as a showmine. From the beginning the "SEEGROTTE" turned out to be a touristic attraction of the first order. Since its opening more than 10 million visitors from around the world visited this former mine, 250 000 of them just last year alone.

During World War II the "SEEGROTTE" was requisitioned by the German military forces. Due to the fact that the subterranean site offered best protection against bombing raids the german "Heinkel Werke" built up an underground aircraft factory inside the far flung tunnels of the "SEEGROTTE". 2000 workers were employed here to produce one of the first jetfighters of the world, the "Heinkel HE 162 Salamander". This plane was one of the secret weapons of the german Luftwaffe. A model of the plane and some original parts are shown inside the "SEEGROTTE". After the war the "SEEGROTTE" was reopened as a tourist attraction.