At the end of 1943, the German air force (Luftwaffe) started to build a command bunker in the Dutch town of Driebergen which was intended to act as the command and control center for defense against the increasing number of Allied bombers attacking Germany and occupied Europe. The bunker, codenamed Cäsar, measured 22 x 22 meter and was 14 meter high. It was camouflaged by painting the exterior concrete walls like a house. However, because of changes in the Luftwaffe leadership, the bunker was never put into use.
After the war, the bunker was taken over by the Dutch air force and they updated the camouflage using real bricks and windows. The strong outer walls of the concrete can still be seen through these windows. In 1991, Dutch air force ceased to use the bunker and in 1995 it was sold to a private company.