Góry Sowie, the oldest mountain range, hides many secrets, not only geological ones. The stronghold Srebrna Góra was built by the king of Prussia Frederick II to protect the pass. Never conquered, it has become a monument of military technology.

During World War II the Germans began to drill kilometres of tunnels as well as gigantic factory halls in the hard rock of Góry Sowie. This was the implementation of the secret plan "Riese".