Seegrotte, Thermenregion Travel Guide

4.4 (982)

Explore Europe's largest underground lake and discover a hidden WWII aircraft factory in this fascinating Austrian grotto.

Descend into the depths of a former gypsum mine and discover Europe's largest underground lake at the Seegrotte in Hinterbrühl. Explore the fascinating tunnels, ride a boat across the emerald-green lake, and uncover the site's intriguing history, including its use as a secret Nazi aircraft factory during World War II.

A brief summary to Seegrotte

Grutschgasse 2a, Hinterbrühl, 2371, AT
Click to display
Click to display

Monday 9:30 am-4:30 pm
Tuesday 9:30 am-4:30 pm
Wednesday 9:30 am-4:30 pm
Thursday 9:30 am-4:30 pm
Friday 9:30 am-4:30 pm
Saturday 9:30 am-4:30 pm
Sunday 9:30 am-4:30 pm

From Eve

Know before you go

Hi, I'm Eve. Here are a few practical things to know before exploring Seegrotte.

Wear warm clothing and sturdy shoes, as the cave temperature is a constant 9°C (48°F).
Book tickets in advance, especially during summer months and weekends, to avoid long waiting times.
Photography is allowed, but flash may be restricted to preserve the cave's environment.
The Seegrotte is an ideal place to visit in bad weather, as it is entirely underground.

Do you manage this location?

Take control to get all the benefits, like improved information, better appearance, and stronger visibility across AI-powered discovery. Learn more about listing your business on Evendo

Activate your presence

Other nearby places you may find interesting

The closest places of the same kind, if this one is not quite what you had in mind.

Römerwand

Föhrenberge Nature Park

Burgruine Mödling

Kalenderberg

Husarentempel

Explore Seegrotte on the Map

A handpicked selection of must-see spots near Seegrotte, mapped for you.

Getting There

Public Transport

From Vienna, take a train to Mödling Bahnhof. From there, take bus line 264 to Hinterbrühl Beethovengasse. The Seegrotte is a short walk from the bus stop. A single bus fare from Mödling to Hinterbrühl costs approximately €3-€15. The train journey from Vienna to Mödling takes approximately 57 minutes.
Car

From Vienna, take the A21 motorway to Hinterbrühl. Follow signs to the Seegrotte. Parking is available near the Seegrotte, a short walk away. Parking availability may be limited. Be aware that some parking lots may have hourly or daily rates.

Discover more about Seegrotte

The Seegrotte, located in Hinterbrühl, Lower Austria, offers a unique blend of natural wonder and historical intrigue. Originally a gypsum mine dating back to the 19th century, a blasting accident in 1912 flooded the lower caverns, creating a vast subterranean lake. Abandoned for nearly two decades, the grotto was rediscovered in the 1930s and transformed into a tourist attraction.A guided tour takes you through the old mine tunnels, revealing the history and geology of the site. You'll see remnants of mining operations and learn about the miners' chapel dedicated to St. Barbara. The highlight is the boat ride on the 6,200 square meter underground lake, where the water's emerald-green surface and the cave's acoustics create a mystical atmosphere.During World War II, the Seegrotte was used by the Nazis as a secret underground factory for producing parts for the Heinkel He 162 Salamander jet fighter. Forced laborers worked here under harsh conditions, and a monument above the lake commemorates the victims of this dark chapter in history. The Seegrotte is open year-round, with tours available in multiple languages. Remember to wear warm clothing and sturdy shoes, as the temperature inside the cave remains a constant 9°C (48°F).