Monheim am Rhein, in the Mettmann district, North Rhine-Westphalia
The Jenoptik Group headquarters are in Jena, with additional major sites in Germany located in Wedel near Hamburg, Monheim and Ratingen near Düsseldorf, Villingen-Schwenningen, Triptis, the Bavarian town of Altenstadt, and Essen.
For a time it was assumed that the house also functioned as a synagogue, Monheim having had a Rabbi since 1715, but this has since been disproven.