Remains of the fortifications built by the Germans in 1944 to close the Viamaggio Pass to any Allied advance from the Tiber Valley towards Rimini or Pesaro are visible. It is a sort of "horseshoe" that embraces the road crossing. In each of the sites, remains of trenches, connecting paths and shelter and shooting positions are still visible. They are mostly found around 900 meters above sea level; immediately below, at the time, an interdiction zone protected by barbed wire and a large area of minefields were placed (which continued to create problems even after the retreat of the Germans: first for the Allies to reach Badia Tedalda, and then for the people local; in the following years there were several deaths and injuries due to mines).