Vršič mountain pass (1.611 m) is linking the Upper valley of Sava River with the valley of Trenta. The road across the pass was built for military purposes and opened in the year 1915 (spring 1916). The road over the pass is currently known as Ruska cesta ("Russian Road") - so renamed in July 2006 to honor the Russian prisoners of war who had been forced to build it.
The first Russian prisoners of war came to the territory of present-day Slovenia in september, 1914 and were brought to Kranjska Gora. Most of them worked on the construction of a reserve battle line along the Isonzo Front between Kranjska Gora, the Isonzo Valley, and around the forest of Trnovski gozd. By far the biggest project was the construction of a road across Vršič Pass from Kranjska gora to Trenta.