Jasenovac (pronounced [jasěnoʋat͡s]) is a village and a municipality in Croatia, in the southern part of the Sisak-Moslavina County at the confluence of the river Una into Sava. In Croatian "jasen" means ash tree and the name Jasenovac means "ashen, or made of ash tree".
Jasenovac attained notoriety during the Holocaust through the Jasenovac concentration camp giving its name to the Ustaše complex of WWII concentration camps in the context of the Genocide of Serbs.
The Una (Serbian Cyrillic: Уна, pronounced [ûna]) is a border river between Bosnia and Herzegovina and Croatia and a right tributary of the Sava river. It is part of the Black Sea drainage basin, and its watershed has a size of 10,200 km (3,900 sq mi), of which 8,080 km (3,120 sq mi) belongs to Bosnia and Herzegovina, and 2,120 km (820 sq mi) to Croatia. The total length of the river is 212 km (132 mi). The source of the river is located near the village of Donja Suvaja in Croatia, and its mouth is located near the village of Jasenovac, on the border with Bosnia. The largest right tributaries are the Krka, Unac, Krušnica and Sana rivers, and the largest left tributary is the Klokot river. Its longest headwater is the Unac river. The largest and most important city located on the river is Bihać. Other, important cities and towns are Bosanska Krupa, Bosanski Novi and Bosanska Kostajnica. The river is characterized by a multitude of waterfalls, rapids, karst springs and relatively untouched nature. A large part of the upper river is part of the Una National Park.
Jasenovac (pronounced [jasěnoʋat͡s]) was a concentration and extermination camp established in the village of the same name by the authorities of the Independent State of Croatia (NDH) in occupied Yugoslavia during World War II. The concentration camp, one of the ten largest in Europe, was established and operated by the governing Ustaše regime, Europe's only Nazi collaborationist regime that operated its own extermination camps, for Serbs, Romani, Jews, and political dissidents. It quickly grew into the third largest concentration camp in Europe.
The camp was established in August 1941, in marshland at the confluence of the Sava and Una rivers near the village of Jasenovac, and was dismantled in April 1945. It was "notorious for its barbaric practices and the large number of victims". Unlike German Nazi-run camps, Jasenovac lacked the infrastructure for mass murder on an industrial scale, such as gas chambers. Instead, it "specialized in one-on-one violence of a particularly brutal kind", and prisoners were primarily murdered with the use of knives, hammers, and axes, or shot.