
As of April 30, 1939, the anti-Semitic legislation of the Nazi regime deprived the Jews in the German Reich of their protection as tenants. Subsequently, they were urged or forced to move to segregated Jewish living quarters that isolated them from their former non-Jewish neighbors who often willingly participated in their exclusion. These places were the last living places for most German Jews before their deportation.
https://de.wikipedia.org/wiki/Judenhaus
"Judenhäuser" existed in many towns of the German Reich, e.g. in Heidelberg.
http://www.s197410804.online.de/Stadtgeschichte/1933-1945/Judenhaeu...