Original nesting box ( Bird Box) from the Obersalzberg bird sanctuary, Kehlstein. Between 1937 and 1942, a large number of numbered nest boxes were hung within the restricted area. An ornithologist supervised the project, which had been ordered by the highest authority Martin Bormann. The box here was taken from a tree in 1993, along with several other boxes, in the Kehlstein woods while researching a book ( History of the Eagle’s Nest : a Complete Account of Adolf Hitler’s Alleged “Mountain fortress” ). The small plastic label with the number has unfortunately broken off. At the time, the numbers had to be written by hand on the signs by employees of the Obersalzberg administration. (The first numbering system was changed in 1938, which is why there are even lower numbers on the back of some plates).