This study focused on improving the understanding of the actual extent and spatial impacts of the Rupnik Line as one of the two fortification systems of the Rapallo Border. To this end, the available sources were checked and the understanding about the sectoral division of the Rapallo Border’s elements was derived therefrom. The field investigation done at a micro-location level revealed the real scope of the Rupnik Line fortification facilities. By identifying and recording the individual Rupnik fortification facilities in the Municipality of Žiri and by conducting interviews, we made an overview map showing the locations of these fortification structures. This basis, testifying to the actual condition and extent of the Rupnik Line fortification system at the level of the Municipality of Žiri, made it possible to develop further in-depth research questions regarding the spatial roles and values of this system.