Banja Luka or Banja Luka is the second largest city in Bosnia and Herzegovina and the largest city in the Republic of Srpska. It is located in the middle of the dense forest of Bosnian Krajina in northwestern Bosnia. According to the 2013 census, the city has a population of 138,963, while its administrative area counts a total of 185,042.

Banja Luka is the administrative, political, financial, university and cultural center of the Republic of Srpska. The city lies on the Vrbas river and is known in the countries of the former Yugoslavia for its greenery and alleys, boulevards and parks. The most common tree of urban greenery is wild chestnut, along with linden and spruce.

Banja Luka was declared the European City of Sports in 2018.
The official City Day is April 22. On that day in 1945, the Sixth Krajina Brigade, led by Commander Milancic Miljevic, marched triumphantly into Banja Luka, liberating it from the fascists.
Banja Luka was first mentioned in 1494 in the charter of the Hungarian king Vladislav II Jagelovic, issued in Buda in Latin language, although the city existed before. Archaeological sites and objects found provide evidence of the existence of human communities since the Mousterien Era from 50,000 – 35,000 BC.

In the city’s immediate surroundings there are three springs of thermo-mineral water whose healing effects have been known since the ancient times.

Banja Luka has a temperate humid subtropical climate with mild winters, mild frosts and warm summers. The warmest month is July, with an average temperature of 22.8° C (73.0° F). The coldest is January, with 1.7° C (35.1° F). The city has an average of 104 rainy days and has snow almost every year during the winter period.