U-Verlagerung Zement: UNDERGROUND Report (AT) -

The underground factory „Zement“ near Ebensee, Austria, was part of Nazi Germany’s broader effort to relocate key war production underground to protect it from Allied bombings. Originally, the site was planned for the development of A4 (V2) rockets, but as the war progressed, those plans were abandoned. Instead, the tunnels were repurposed for fuel refining and the production of engine parts for military vehicles. This facility was part of the Geilenberg program, which aimed to secure fuel supplies for Germany in the final phase of the war.

Construction of the underground complex began in 1943, with most of the work done by prisoners from the nearby Mauthausen concentration camp. These prisoners were forced to work under brutal conditions. Approximately 27,000 prisoners were subjected to forced labor in Ebensee, and over 8,500 of them died due to the inhumane treatment. By the time the site was liberated by U.S. forces in May 1945, more than 18,000 prisoners remained, many of whom were severely ill.

In addition to these details, it is important to note that the original plan to relocate rocket research and production to Ebensee was abandoned after the heavy bombing of Peenemünde in 1943. Instead, two main tunnel complexes—facilities A and B—were quickly adapted for other war-related purposes, particularly oil refining and fuel production. The project was codenamed „Cement,“ and the tunnels were rapidly modified to accommodate war production.

Today, parts of the tunnels are open to the public as a memorial, honoring the victims of forced labor and the atrocities committed at the site.