Soon after the fort at Lago del Predil was completed, it became clear that it could not be an effective artillery stronghold. For that reason, the Austrians built another fort on the Sella Predil saddle above the lake, the Sella Predil Battery, which served as a support to the Predil fortification and controlled the road towards the Sella Nevea saddle and towards Predil/Predel. It was built in 1899, but since the plans dated back to 1892, it was necessary to modernize it as early as 1906, when an armoured observation post was added and the roof was covered with a 50–75 cm layer of concrete. Despite its modernization, the fortress was out-of-date at the outbreak of World War I. Another problem was its position, oriented towards the Sella Nevea saddle and thus fully exposed to Italian artillery. Between May 25 and June 21, 1915, the Austrians managed to move one-by-one three 120-mm guns from the fort to two higher-lying rock caves on the southwestern slope of Cima Predil/Predelske glave (called Predilkopf during the war). All supplies were likewise taken from the fort.
The Italians continued to shell the fort, emptied of arms, until the end of July, when they realized that two guns had been shelling from a cave above the fort. All until the end of World War I, the Italian attempts to hit the cave failed.
Despite the fact that the fort was hit by 50 shells of the heaviest calibres, it remained relatively undamaged. After 1945, when the border ran only a few hundred metres east of the fort (where it still runs today), the Italians blew up the artillery casemates and used the fort as a border position.
From the A23 motorway, take the Tarvisio/Trbiž/Tarvis exit, then follow the signposts for Cave del Predil/Rabelj/Raibl along the SS54 state road. After Cave del Predil, continue along the provincial road SP76 to the lake. At the fork, turn left towards Slovenia.