The Julian Alps have been of military significance since Roman times in a military geographic sense because of its valleys, mountain passes and lines of defence on mountain ridges. They became especially important in the 19th and 20th century. The largest mountain front in World War I was located there,and evidence of that front is still visible today. The border between Italy and Yugoslavia in the heart of the Julian Alps was clearly a line of demarcation along the Soča and Sava watersheds and was reinforced with fortification, obstacles and trenches. During the Cold War, there was an ideological line of demarcation along the western edge of the Julian Alps as well. Military strategy in that area included the use of military geographic approaches in both westerly and easterly directions. After the geopolitical changes of 1991, the Julian Alps no longer had same military geographic significance in terms of Slovenian national security. Today other military activities are more important: training under mountains conditions for NATO soldiers, non-commissioned and commissioned officers takes place in the Pokljuka region and on the Triglav mountain chain. Military facilities have been taken on significance in the terms of tourism as well.