1944 Mauthausen Concentration Camp.
Postal card sent from Nowy Sącz to Mauthausen Concentration Camp sub-camp Linz AKL and returned to sender Zygmunt Podhalanski - he was in two camps, Auschwitz and Mauthausen, and worked in the metal industry and in construction work. He survived the war.
Correspondence sent to the camps is extremely unique due to the prohibition and the possibility of storing anything.