The owner inherits a built environment that he has have to protect, care for, (trans-)form, and in the end, transmit to his descendants. Every time this cycle does not occur, a part of the built heritage is doomed to be degraded and even disappear. As from the moment its construction ends the beginning of an edifice's decay is inevitable, in order to preserve it in a good state, it has to be maintained. Any edifice which is not preserved may be called an endangered one. The purpose of this exhibition and of the publication is therefore the drawing of attention over the endangered built heritage.