Slunj (Hungarian Szluin, old German Sluin, Latin Slovin, archaic Croatian Slovin grad) is a town in the mountainous part of Central Croatia, located along the important North-South route to the Adriatic Sea between Karlovac and Plitvice Lakes National Park, on the meeting of the rivers Korana and Slunjčica. Slunj has a population of 1,674, with a total of 5,076 people in the municipality (2011) and is the cultural and social center of the region of Kordun in the vicinity to Bosnia and Herzegovina. Administratively, the town is part of Karlovac County. Slunj is underdeveloped municipality which is statistically classified as the First Category Area of Special State Concern by the Government of Croatia.
An old fortification of the Frankopans, built during the wars against the Turks, Slovin was first mentioned in the 12th century. The old fort was property of the Frankopan (Hungarian Frangepán) family since the 15th century, joined by an old Franciscan monastery from the same period. Later, this town has been called Slunj. In the 16th century the town was ravaged by the Ottoman wars and turned into a military outpost of the Croatian Military Frontier, but by the end of the 17th century the settlement was rebuilt into the Slunj as it exists today. The castle has been developed to a fortress and served as headquarters for the commanding general of this area (see Stari grad Slunj). After the Treaty of Sistova in 1791 people increasingly began to re-settle in this area.