NišavaThe Nišava is a river that flows through Bulgaria and Serbia and with a length of 218 km is the longest tributary of the South Morava River. The Nišava springs in Bulgaria under the Kom Peak in Stara Planina. Its source is near the border with Serbia, so that the Nišava flows through Bulgaria only 67 kilometers, with no major tributaries. After passing through the village of Ginci, the river is also known as the Ginska. Its course first goes south, then sharply turns west into Godech valley, passes through the village of Razboište, after which it forms a gorge. Out of the gorge, there is village Kalotina, which is a border checkpoint between Bulgaria and Serbia (Kalotina-Gradina), and the river continues to the west through Serbia. Flowing 151 km mainly to the west, the Nišava passes through Dimitrovgrad, Pirot, Bela Palanka, Niška Banja and Niš. About 10 kilometers after Niš, it flows into the South Morava River. The Nišava belongs to the Black Sea basin and its catchment area covers a territory of 3.950 km² (1,237 km² in Bulgaria, 2713 km² in Serbia). Today, the Nišava is not a navigable river, but in ancient times it was. Nišava has many small tributaries, such as the Temštica and the Visočica on the right, and the Jerma, the Crvena Reka, the Koritnica and the Kutinska rivers on the left.
The valley of the Nišava is part of the natural road from the ancient times which connected Europe and Asia: the road follows the valleys of the Morava, the Nišava and the Marica and goes on to Istanbul.
Roads and railroads Belgrade-Sofia-Istanbul follow this path.