"My father and Kazik were taken to the concentration camp of Sachsenhausen"

 Sachsenhausen was one of the original concentration camps established by the Nazis.  Built in 1938, it was located 35 km from Berlin.  It was originally designed as a holding camp for political prisoners and prisoners of war.

The practice of cruel and inhumane medical experimentation was developed within the camp.  A great deal of slave labor was provided through Sachsenhausen. The camp became a training ground for future concentration camp directors, and many of the more atrocious ideas of the extermination camps were developed here. 

U. S. Holocaust Memorial Museum

Sachsenhausen Virtual Tour