Shadows of a Forgotten World

During WWII, Lviv was occupied by Nazi Germany from 1941 to 1944. The Germans established bomb shelters around the city and marked them with "NA" and an arrow pointing downwards. Some of these signs remain today. "NA" probably stands for "Nachrichten-Abteilung," which means "intelligence unit." These have long gone unused, but, unfortunately, due to a new war, today on the other side of the country there are active bomb shelters . Here are some of the signs. Most of the examples I found are on buildings built in the interwar period. Maybe these were chosen specifically because they were newer buildings and therefore probably structurally more sound than the older Austrian-era buildings.

In Vienna one can still find the covers to WWII civilian bomb shelters. Originally I thought these metal grates were either storm drains or vaults lights with missing glass, but I discovered that in fact they were covers for ventilation shafts and emergency exits. Across the territory of Nazi Germany basements in cities were designated as bomb shelters and sometimes ventilation shafts and emergency exits were built from them and covered by special covers. On the outer walls of these buildings "LSR" was painted in white along with an arrow pointing to the entrance. Emergency exits were marked with arrows and the letters "NA" ( examples of which can be found even in Lviv ). The air-raid covers that I found were made by a company called Mannesmanm.  "Luftschutz" means air-raid.