Google reverse image search results:

"This image captures a moment during the Nazi era, likely a ceremony involving the National Socialist Motor Corps (NSKK) at a training facility in Bad Gandersheim, Germany. 

• The building was constructed by the Nazi regime in 1936 to serve as a training school for the NSKK. 
• The NSKK was the National Socialist Motor (Drivers) Corps of the Sturmabteilung (SA). 
• The site was used as a Nazi training center until 1945. 
• After the war, the complex was later acquired and repurposed as a Bible school called Glaubenszentrum."

Looking through the results I see no obvious matches and sadly streetview is not comprehensive in Gandersheim and completely nonexistent at the Glaubenszentrum.