Deep beneath our feet lies a hidden world. The Kleine Grotte awaits us. It is a tunnel system in the Park an der Ilm. It sits twelve meters deep. It lies between the steep slope to the Ilm and Belvederer Allee.
The Kleine Grotte owes its existence to Duke Carl August. He wanted his own brewery. Between 1794 and 1796, a roughly 500-meter-long tunnel was dug. It was meant to divert the brewing water for the planned brewery. The brewery plan was dropped. The tunnel was used for sand and gravel extraction from 1797 to 1815. This created an extensive system of passages and tunnels.
Later during the Second World War a part of the Kleine Grotte was converted into a bunker. This area now houses the museum of the Park Cave.
To reach the Kleine Grotte a staircase near the Liszt House leads down to the tunnel. The tunnel ends at the so-called Needle’s Eye. This is an artificially created rock gate on the Ilm.
The tunnel of the Kleine Grotte passes through layers of river gravel. It also goes through alluvial sediments of the Ilm. Fossils of plants and animals from a prehistoric lake can be found on the ceiling.
The Kleine Grotte has a rich history. It was created in the Goethe era. For decades it was unused. Near the end of the Second World War, it was expanded into a shelter. It has been accessible again since 1997. This was interrupted by a pandemic and a complete renovation.
In 1797, the tunnel system was used as the castle’s brewery cellar. The Weimar town hall decided to use the facility as an air raid shelter on April 13, 1944. Italian prisoners of war and inmates from the Buchenwald concentration camp carried out this heavy underground work. The memory of the time spent together in the Ilm park caves during the air raids plays a role in the war stories of older Weimar citizens to this day. In 1945, small rooms in the park cave were converted to serve as a command center for the Thuringian Gauleitung.
Today you can visit parts of the tunnel system. Forced laborers and prisoners extended it. The entrance is located next to the Bauhaus University canteen. A small exhibition provides information about the history of the Kleine Grotte.
You can visit the Kleine Grotte. It is open from Wednesday to Monday. During the summer season from March 21st to November 1st, it’s open from 10:00 AM to 6:00 PM. In winter from November 2nd to March 20th, it’s open from 10:00 AM to 4:00 PM. It is closed on Tuesdays. There may be special opening hours on public holidays. Tickets for the Kleine Grotte are available only there. They cannot be purchased at other ticket offices or online.
The Kleine Grotte stands as a testament to Weimar’s layered past. It is a place where history, geology, and human resilience converge. A visit here is more than a tour. It is a journey through time.