In April of 1942, 4,000 Yugoslavian partisans watched some 40,000 Nazis and local fascist forces head directly towards their location in the city of Dera with the express goal of wiping them from the face of the planet. 

During the spring of 1942 the Croatian army, Ustaša militia, and the German Wehrmacht surrounded the town of Banja Luka, and over the ensuing weeks, 80,000 civilians were wounded, 1,700 partisans killed, and 50,000 civilians were sent to concentration camps. In early July, a group of partisan forces was finally able to break the siege, but the human cost had already been paid.  

To honor this tragic battle, the Kozara Memorial monument was erected in 1972. Designed by Dušan Džamonja, and built atop Mrakovica Mountain on a plateau surrounded by dense forest, the segmented tower stands 33 meters high. To honor the fallen dead, the names of 9921 of the Yugoslav partisans who gave their life for freedom during the World War II offensive are inscribed on a bronze memorial wall near the tower.