The most beautiful cultural heritage site is the fortress Kastel, built by Ancient Romans and fortified by Ottomans settled next to the green Vrbas River. Vrbas River is perfect for water sports-rafting and kayaking, for example. Numerous cultural events take place in Banja Luka and the most visited and popular are Banja Luka Summer Festival, Kastel Fest (Ljetne igre), etc.

Banja Luka is also one of the 95 places in the world where Trappists, a Catholic holy order founded in France and known for their famous chees, can be found. Population is estamite to be between 250.000 and 300.000.