Start from Belgrade and drive to the city of Smederevo. In the 15th Century, Smederevo became the capital of Serbia and the fortress was built in a very short period of time. Built at the confluence of the Jezava and Danube rivers on the orders of Serbian Despot Djuradj Brankovic, it was the biggest low-land fortress in Serbia. Visit Viminacium archaeological park, once the capital of the Roman province of Moesia Superior. See the bust of Constantine the Great and 17 more Roman emperors born in Serbia, as well as the amazing mosaic decorated floor. A special attraction here is the paleontological park with a mammoth skeleton discovered at a depth of 27 meters (one million years old). Drive to Golubac fortress, built on the rock at the entrance to the Iron Gates. Built in the 14th Century, this fortress was once under the rule of Hungarians, Serbs, Turks, and Austrians. With strong walls and an ideal strategic location, this fortress has never been overrun. Located at the point where the 6 kilometers wide Danube enters the narrow passage through Djerdap Gorge, this stronghold controlled the navigation on Danube River.