Atomic Cellar

Useful Information

Location: Pfluggasse 5, 72401 Haigerloch.
In Haigerloch, right below the Schloßkirche (castle church) at the bottom of the valley. A81 Stuttgart-Singen, exit Empfingen, about 20 km to Haigerloch. 40 km from Tübingen.
(48.367106, 8.804176)
Open: MAR to APR Sat 10-12, 14-17, Sun, Hol 10-17.
MAI to SEP Mon-Sat 10-12, 14-17, Sun, Hol 10-17.
OKT to NOV Sat 10-12, 14-17, Sun, Hol 10-17.
Easter and autumn school holidays Mo-Sa 10-12, 14-17, Sun, Hol 10-17.
Fee: Adults EUR 4, Pupils EUR 3.
Groups (10+): Adults EUR 3.
Guided tour per group EUR 50.
Classification: SubterraneaTunnel SubterraneaCellar SubterraneaUnderground Museums unfinished railroad tunnel, former beer cellar and laboratory.
Light: LightIncandescent Electric Light System
Guided tours: For groups (10+) after appointment.
Photography: allowed
Accessibility: yes
Bibliography: Wolfgang Menge (1991): Ende der Unschuld, Die Deutschen und ihre Atombombe. Das Buch zum Film. Volk und Welt 1991 Br 280 S. 21 x 15 cm, ISBN 3-353-00841-1 (Deutsch - German)
Michael Thorwart, Egidius Fechter (2001): Haigerloch Cave Survived the War, Physics Today 54, 4, 93 (2001). online DOI pdf
Timothy Koeth, Miriam Hiebert (2019): Tracking the journey of a uranium cube, Physics Today 72, 5, 36 (2019). Tracking the journey of a uranium cube DOI pdf
Hans A. Bethe (2000): The German Uranium Project, Physics Today 53, 7, 34 (2000). online DOI pdf
Friedwardt Winterberg, Günter Herrmann, Igor Fodor, Lincoln Wolfenstein, Mark E. Singer (1996): More on How Nazi Germany Failed to Develop the Atomic Bomb Physics Today 49, 1, 11 (1996). DOI pdf
Address: Atomkeller-Museum Haigerloch, Egidius Fechter, Kultur- und Verkehrsamt, Postfach 54, 72394 Haigerloch, Tel. +49-7474-69727. E-mail:
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
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1901 tunnel built for the Hohenzollerische Eisenbahn (railroad of Hohenzollern).
???? beer cellar of the landlord of the Schwan (swan restaurant), Otto Merz.
1944 rented by the Kaiser-Wilhelm-lnstitut für Physik (Kaiser Wilhelm Institute for Physics) in Berlin.
23-APR-1945 occupied by american soldiers Keller which disassembled the whole facility.
1980 small scientific museum about the atomic research opened.
1991 some scenes for the German TV film Das Ende der Unschuld (The End of Innocence) about the German atomic research and the first atomic bomb were filmed here.


Soldiers of the ALSOS mission playing with uranium cubes.

This subterranea is a central place of World War II and nuklear science history: it is the place where the first atomic reactor of the World was built. Because of air raids and destruction, a group of physicists had to leave Berlin. They were making experiments with a first atomic reactor unter the guidance of Prof. Werner Heisenberg which were continued in this tunnel from 1944 on. Scientists who worked here were Carl-Friedrich von Weizsäcker and Karl Wirtz.

The Atomkeller (atomic cellar) is a long, rectangular room, the walls are the rough, undisguised rock face. The whole tunnle reminds its original origin: an (uncompleted) railroad tunnel. The reactor prototype was once located at the end of this tunnel. The entrance to the tunnel is barred with a huge wooden door.

To be exact, the atomic reactor which was built here was never intended to produce energy. It was the first attempt to produce any kind of reaction by the refinement of the uranium and the bombardment with neutrons. The resulting neutron emissions of the uranium were measured. This most famous experiment carried out at Haigerloch was called Experiment B8. But as anybody today knows, there is a critical mass of uranium at which the chain reaction of the atomic bomb starts. The scientists at this time had little knowledge about this, and it is mere luck, that they never made an experiment with a critical mass. To be precise, they did not have enough material because of the war.

This place, in a small sleepy village with boxwork houses, in this rural area of Swabia, was chosen because of its remote location. Air raids were rather unlikely and the subterranean place provided additional security. But definitely the relevant reasons, for the decision to come here, was the safety of the facility, not the safety of the common people. And of course, the dangers of the atomic technology and the unhealthy consequences of radiation were mostly unknown. However, they would have been of little relevance to the rulers of that time.

But the ignorance of harmful consequences of radioactive material is also demonstrated by a photograph which is on display here. American soldiers, a few days after they took the village, were ordered to look for any kind of valuable technology. They found the uranium cubes, the German scientists buried in the outside entry area, before they fled. Ignorant of the danger of this material, they played with them and built funny little towers, posing for the photographer. The radiation was definitely not harmless, and they could have reached the critical mass while playing.

Today the whole tunnel is used for a museum about the atomic research in Germany during the war. Replicas, models and photographs give a brief introduction into the state of nuclear science at that time. The original contents of the laboratory are mostly destroyed. The research reactor is reconstructed.