 Complete the following phrase:  The project plan provided for 72 km of trenches, 88 artillery positions including 11 built in caves, 25,000 square meters of barracks, 296 kilometers of roads and 398 kilometers of mule tracks, at a cost of over 105m lire about 150m euros today, requiring 40,000 men to build it. This complex of works was never used. The fortifications were garrisoned at the beginning of the war but abandoned after the defeat at 