Golubac is a medieval fortress located some 130 kilometers away from Belgrade. It stands on the bank of the Danube river. The river here acts as a border between Serbia and Romania and is rather wide - it is hard to see the other bank.
The fortress was built during the 14th century by Medieval Serbian state. It has had a tumultuous history, as it repeatedly passed between Turks, Bulgarians, Hungarians, Serbs and Austrians, repelling over 120 attacks during its history. The location is strategically significant - the river narrows into a gorge here, making the fortress a gateway to the Danube.
The fortress consists mostly of towers. The lower towers are accessible to all visitors. The upper towers are not open all the time, and when they are, they are only accessible to visitors older than 18, and shoes and clothing suitable for climbing are required.
Although it takes less than an hour to explore the fortress, it is certainly worth the visit, as the place is incredibly beautiful.