Niš is the largest city of southern Serbia and the third-largest city in Serbia (after Belgrade and Novi Sad). It is the administrative center of the Nišava District.

According to the 2011 census, the city has population of 183,164, while urban area of Niš (with adjacent urban settlement of Niška Banja included) has 187,544 inhabitants, and population of metro area stands at 260,237 people.

The University of Niš (Serbian: Универзитет у Нишу / Univerzitet u Nišu) is a university in Niš, Serbia. It was founded in 1965 and it consists of 13 faculties with 1500 teachers, 630 staff and extracurricular staff, and around 30,000 students. It has a university library "Nikola Tesla"; the Faculty of Technology is in Leskovac and the Teacher-Training Faculty is in Vranje.

Niš is one of the oldest cities in the Balkans and Europe, and has from ancient times been considered a gateway between the East and the West. It was named Navissos by the Scordisci in 279 BC, after an invasion of the Balkans. The city was among several taken in the Roman conquest in 75 BC; the Romans built the Via Militaris in the 1st century, with Naissus being one of its key towns; it is also the birthplace of Constantine the Great, the first Christian Emperor and the founder of Constantinople, and Constantius III and Justin I. It is home to one of the oldest churches in Serbia, dating to the 4th century, located in the suburb of Mediana.

Niš is one of the most important industrial centers in Serbia, a center of electronics industry (see Elektronska Industrija Niš), industry of mechanical engineering, textile and tobacco industry. Constantine the Great Airport is its international airport. In 2013 the city was host to the celebration of 1700 years of Constantine's Edict of Milan.

The town was named after the Nišava River, which flows through the city and which was named Navissos by the Celtic masters of the city in the 3rd century BC; it was then known as Roman Naissus, Byzantine Nysos and Slavic Niš. Legend has it that Niš was founded by a Prince Nisa, who built it using the nearby Humska čuka stone.

Niš is situated at the 43°19' latitude north and 21°54' longitude east, in the Nišava valley, near the spot where it joins the South Morava. The main city square, the city's central part, is at 194 m (636 ft) above sea level. The highest point in the city area is "Sokolov kamen" (Falcon's rock) on the Suva planina (Dry Mountain) (1,523 m (4,997 ft)) while the lowest spot is at Trupale, near the mouth of the Nišava (173 m (568 ft)). The city covers 596.71 square kilometres (230 sq mi) of five municipalities.

The road running from the north down the Morava River valley forks into two major lines at Niš: the southern line, leading to Thessalonica and Athens, and the eastern one leading towards Sofia and Istanbul.

Average temperature in September, when Days of Applied Psychology take place, is 17.4 °C, and typically ranges between 11 °C and 25 °C during the day.  Average annual temperature in the area of Niš is 11.2 °C (52.2 °F). July is the warmest month of the year, with an average of 21.2 °C (70.2 °F). The coldest month is January, averaging at 0.2 °C (32.4 °F). The average of the annual rainfall is 567.25 mm (22.33 in). The average barometer value is 992.74 mb. On average, there are 123 days with rain and snow cover lasts for 45 days.

Nišville jаzz festivаl is an international jazz festival that takes place in Niš, and with a decision of Ministry of Culture of the Republic of Serbia is marked as an event of ”National Importance”. Nišville also gets award ”Best from Serbia” in 2011 and award ”Tourist Flower” as the best manifestation in Niš. Nišville is held in Niška tvrđava (Niš fortress) each August.

Source and read more on: http://en.wikipedia.org/wiki/Ni%C5%A1