While General Conrad was preparing his great action on the Asiago plateau, the war went on even around Falzarego Pass that had been conquered by the Italians in June 1915. For tactical purposes it was of fundamental importance to have under control the surrounding peaks so as to clear the road leading toAlto Adigeand toTrento, a location that was a symbol of Italian irredentism. But the Austro-Hungarian emplacements were very strong and did not allow the Fourth Army to advance.
With the passage on Valparola blocked, in the autumn of 1915 the Italians tried to cross the wild Val Travenanzes in a northward direction and to conquer the peaks of the range of the Tofane. On the other hand, on the road that led to Bolzano and to Trento in a westward direction, the Italians set their sights on the twin peaks of Col di Lana (2,450 metres), two kilometres away as the crow flies from Sass di Stria.
Despite the difficulties on land (the Col di Lana has very steep walls) 12 infantry battalions and 14 Alpine battalions continued this attack throughout the whole of autumn. The attack ended on 08th November 1915 with the conquest of the peak to the great surprise of the Austrians themselves who did not expect such an insistent action. But the counter offensive that left from Sief, a peak not far away to the west, allowed the Habsburg forces to take back the Dolomite mountain.
The attacks did not stop, not even in December (12th-19th) under the snow and in the cold winter days but the Italian army lacked weapons that were suitable to beat the Austro-Hungarian army. In January 1916 a final decision was taken to place a mine underneath the mountain top to eliminate forever the presence of the Habsburgs and free the pass in a westward direction. For more than three months a long underground tunnel was excavated and armed with about five tons of gelignite that were exploded at 11.30 pm on 17th April.
Half of the Austrian contingent was killed by the collapse of about 10,000 tons of rock while the other 140 soldiers were captured and imprisoned when the Italians reached the summit. The road was not, however, free as yet: in order to control the passes leading to the north and to the west, it was necessary to free definitely even the peak of the Sief. The attacks continued until October 1917 (even with the installation of another mine) but the Austro-Hungarian defence was insurmountable. The corridor towards Trentino remained blocked.
