The terrain in Austria is significantly noticeable by its large proportion of mountains, as two thirds of it are covered by the Alps. In order to utilise these circumstances, several buildings were installed in high altitude, put underground, and connected by kilometres of tunnels. As these institutions are of great importance for the population, they can be considered as critical infrastructures which the Austrian Armed Forces might need to protect in the future. Therefore, it is necessary to draw the lines between the mountaineer and subterranean troops to increase cooperation.