The municipality of Mali Zvornik is located on the right bank of the swift and rapid Drina, surrounded by the Gučevo mountain to the north and the Boranja and Jagodnja sub-Drinine mountains to the east. A place where there are traces of human life since the Bronze Age, as evidenced by numerous archaeological remains. It is assumed that right between the two namesakes, Zvornik and Mali Zvornik, there was an ancient Roman settlement Ad Drinum. The empires and their leaders have always fought for this part of Podrinje: the Austarians, the Skordis, the Drinjans, the Romans, the Nemanjićs, the Dubrovniks, the Turks, the Austrians, the Hungarians, the Karađorđevićs, and others, because it was an important strategic area. In the past, Mali Zvornik was an irreplaceable military fortress. On the Orlovine hill, near Mali Zvornik, there are the remains of a large medieval fortress that was probably built in the first half of the 15th century, during the Serbian despotism. Back in 1919, King Alexander I the Unifier, the great-grandson of Voždo Karađorđević, vowed to bridge the "Drina noble among". The vow of the immortal Leader was fulfilled by his great-grandson, and the bridge was officially opened on January 12, 1930. In the immediate vicinity of the old iron bridge, there is a hill in the heart of which is a whole complex of tunnels and rooms. 1931. an underground city was built, a wartime royal shelter. The shelter, built between the two wars, has an exit to the lagoons of the Roman city of Ad Drinum, which connected both banks of the Drina. There is a passage under the bed of the Drina, which has not yet been explored. It is not a question of any digging under the bed, but that passage was created when the Drina flooded the Roman city long ago, many centuries ago, by widening its bed. Mali Zvornik is unique not only for its rich cultural assets and remains of historical eras, but also for modern industrial assets such as HPP "ZVORNIK" - the first hydroelectric plant on the Drina.