The Danube River flowing through the Kazan Gorge in the Iron Gates Region between Serbia and Romania, Europe

A rock sculpture of Decebalus, last prince of the Dracinians, on a hillside in the Kazan Gorge area of the Danube River, Romania, Europe

A view of the Kazan Gorge from a ship cruising on the Danube River between Serbia and Romania, Europe

Trajan's Plaque, a marble Roman plaque on the banks of the Danube River in the Kazan Gorge region of the river, Serbia, Europe

Aerial of the Kazan Wedding Palace, Kazan, Republic of Tatarstan, Russia, Europe

Aerial of the Kremlin, UNESCO World Heritage Site, Kazan, Republic of Tatarstan, Russia, Europe