Seegrotte Hinterbruhl
About
The Seegrotte Hinterbrühl, also known as the Lake Grotto, sits beneath the town of Hinterbrühl in Lower Austria. This limestone cave system was once a gypsum mine that was flooded in 1912, creating Europe’s largest underground lake that covers more than 10,000 square metres of crystal‑clear water. Guided tours glimmer beneath the water’s surface, allowing visitors to feel the unique, cool atmosphere of the cavernous chambers. The grotto also bears a stark historical significance. Between 1943 and 1945, the Nazi regime sealed off the cave and operated an underground factory that produced parts for the He 162 “Spatz” jet fighter under the most oppressive conditions. Today, the site preserves this history while offering an unforgettable natural adventure. Visitors to the Seegrotte enjoy a combination of geological intrigue, ghost‑laced ambience, and a tangible link to Europe’s wartime past, making it a compelling destination for history buffs and curious explorers alike.
Highlights
- Europe’s Largest Underground Lake
- Gypsum Mine Heritage
- World War II Historical Site