After visiting the above Austro-Hungarian post, the itinerary continues to the Gun tunnel of the Third Army, an underground tunnel network dug by the 20th Diggers Regiment inside Height, 3 between September 1916 and June of the following year.
The gallery develops along two main branches and used to accommodate eight medium-calibre guns (149 mm). The tunnels allowed positioning six guns to the north, towards Gorizia and the Vipacco Valley, and two to south-east, towards the Comeno Karst and Mt. Ermada. From here, the Italian Army could strike both the Austro-Hungarian front and rear lines, where barracks and supply lines were located.
Today, visitors can still observe the concrete bases that used to support these weapons, the corridors and the rooms used by the troops as deposits for materials, infirmary and dormitories. From1917, these spaces accommodated also the Tactical Command of the Third Army.
