Zvornik is a city in Republika Srpska, Bosnia and Herzegovina. In 2013, it had a population of 58,856 inhabitants. Zvornik is located on the Drina River, on the eastern slopes of Majevica mountain, at the altitude of 146m. The town of Mali Zvornik lies directly across the river in Serbia. Kula Grad, a village that is part of Zvornik municipality, has a Middle Age fort, Zvornik fortress, built in the 12th century.