The Nišava or Nishava (Bulgarian and , ) is a river in Bulgaria and Serbia, a right tributary, and with a length of also the longest one, of the South Morava.
Course
Bulgaria
The Nišava originates in western Bulgaria, in the Stara Planina mountains (east of Kom Peak) near the village of Gintsi. Its source is close to the Serbian border. It enters Serbia after of flow through Bulgaria without receiving any major tributaries.
Because it flows through Gintsi, the upper course of the river is known as Ginska (Cyrillic: Гинска). It first flows to the south, then sharply turns west into the Godech Kettle, passing through Razboishte, after which it forms a gorge. Coming out of the gorge, it reaches Kalotina, a major border crossing on the Bulgarian-Serbian border (Kalotina-Gradina), and continues to the west into Serbia.
Serbia
Flowing generally to the west for the remaining , it passes near Dimitrovgrad, Pirot, Bela Palanka, Niška Banja and Niš, one of the largest cities in Serbia, after which the Nišava empties into the Južna Morava. However, with the rapid growth of Niš in previous decades and its still fast growing suburbs, the banks of the Nišava are urbanized almost to its mouth.
Geography
The river belongs to the Black Sea drainage basin. Its own drainage area covers , of which about 73% in Serbia, the rest in Bulgaria. The Nišava is not navigable. It is not only the longest tributary of the Južna Morava, but also the largest one in terms of discharge (). It has many smaller tributaries, the most important being the Temštica from the right, and the Jerma (or Sukovska reka), Crvena reka, Koritnička reka and Kutinska reka from the left.
In its Serbian part, the Nišava carved a composite valley with several depressions (Dimitrovgrad, Pirot (or Basara; Cyrillic: Басара), Bela Palanka and Niš). However, the most prominent geological feature the river formed is the Sićevo gorge. There are numerous caves in the step-like limestone cliffs, majority of which remains unexplored.
Sićevo gorge
The gorge is located between Bela Palanka and Niška Banja. The gorge is long, and deep. The gorge is a composite one, which means in consists of several gorges and widenings, like the Prosečka gorge, Ostrovička basin or Gradištanski canyon.
The river is quite powerful in the gorge, which is used for two power stations ("Sićevo" and "Ostrovica") used for electricity production, irrigation and fishery. The plants are old, from the first half of the 20th century. In some parts canyon like-structures (like inverse valley slopes at Gradištanski canyon) were formed by the river. The gorge itself carved through the Kunovica plateau between the southern slopes of the Mountains of Svrljig and the mountain of Suva Planina, and the surrounding areas are known for their high-quality vineyards. There is also a large Ostrovica quarry in the gorge, where six villages are located, the largest one being Sićevo that gives the name to the whole gorge.
Wildlife
The Oblik rise, above the Sićevo gorge, is a location where extremely rare plants Serbian ramonda and Natalie's ramonda can be found.
Trouts can be find on the entire river's course, with their number varying over the years. Over 100 bird species live only in the gorge section, including golden eagle.
Human history
North of the river, in the Sićevo gorge, excavations in the Mala Balanica cave began in 2005. Mousterian stone tools from the Middle Paleolithic were discovered until 2009. Numerous animal remains were discovered in the same layer, up to deep. A hominid mandible was discovered at the depth of in 2007. It is concluded that it belongs to a young adult person, though the sex can't be specified. Originally believed to be 200,000 to 300,000 years old, during the 2013 examination of the remains it was estimated that the lower jaw was not younger than 397,000 years, and probably older than 525,000 years, which makes it one of the oldest discovered remains of the Homo heidelbergensis in Europe. Later, only further from this finding, remains of Neanderthals were discovered. Four teeth belonged to one adult and one child, and are estimated to be 300,000 years old. It was suggested that some kind of contact of different species of humans happened in the region, one group being from Europe, and the other coming from Asia Minor.