Gamzigrad and Nis, these quite distant places have a lot in common. In Gamzigrad, inscribed on the Unesco World Heritage List, there are the ruins of Felix Romuliana, a magnificent palace complex erected in the 3rd / 4th century by the emperor Galerius. On the other hand, in Nis two emperors were born, Constantine I the Great and Justin I. Quite an unusual attraction of this city is the Tower of Skulls, a reminder of the Serbian national liberation uprisings.