Novo Brdo Fortress

Novo Brdo Fortress is a medieval Serbian fortress in Kosovo. Its ruins are located near the town of Novo Brdo, about 40 kilometres east of Pristina. The fortress was built in the late 13th century by king Stephen Uroš II Milutin of Serbia to protect gold, silver, iron and lead mines which were abundant throughout the area. Novo Brdo was famous for its silver.

Source: Wikipedia