Über Concrete is a type of concrete designed by the ancient society known as the Da'at Yichud.
According to Anya Oliwa, Über Concrete is the essential building block of the Nazi Regime, being based on Da'at Yichud technology and being almost perfect. The only weakness of the substance is that when it deteriorates over time, the concrete starts developing mold. Thus causing people to develop some kind of allergic reaction or become sick off of this mold as it's depicted by several guards in Eisenwald Prison. Though only some Nazi citizens realize that something is wrong, but most citizens just shrug it off and just believe that it's just a coincidence and blame it off of "unhealthy living" by citizens living in cities such as Berlin.
Wolfenstein: The New OrderEdit
The mold on the concrete eventually led to the discovery of Set Roth who was in Camp Belica tampering with the mixture of the substance. The substance that caused the mold was from the use of a limestone that exists only in Northern Croatia.
This discovery led to the Kreisau Circle to send B.J. Blazkowicz to Camp Belica in order to find Set Roth and break him out of the camp. This of course would supply them with an advantage they would need in order to launch an all out counter offensive against the Nazis.
In the mission to find Set Roth; it is therefore shown that the substance is produced in Camp Belica, where they also mine for limestone.