The "Strada delle 52 Gallerie" with its 52 tunnels leads to the Refugio Papa on Mt Pasubio and was constructed in 1917.The 5th Engineering Regiment built the next core section of the trail, called "Strada delle Gallerie" (road of tunnels) under enormous time pressure in only 11 months. This section includes fifty-two tunnels providing cover or leading to the North face of the Italian position. The Strada drops downward in this zone of galleries to about 1200m. The 52 galleries in the aggregate total 2280 meters in length.