It was part of system of Ustaše concentration camps and killing pits, stretching from Gospić, across the Velebit mountains, to the island of Pag.

It was established by Mijo Babić[2] and controlled by the Ustaše, who had been installed as rulers of the puppet state of Croatia by Adolf Hitler and Benito Mussolini.

In September 1941, an Italian army medical team was sent to investigate reports of mass graves contaminating drinking water across the Velebit mountains and on the island of Pag.

[8] Their report includes the following description of how they dug up these mass graves:[9][10]After the first 5 to 20 cm [of earth] removed we saw many hands, often bound (see photo 6), bare feet, sometimes with shoes, heads looking upwards or with necks exposed…Although we had already got used to limbs and heads sticking out, there was something particular about the way they had been buried…The proof that they had been buried mortally wounded but still alive were distorted and terrible facial expressions of the most corpses….In some places there were five layers of corpses, in some less…We found machine gun shells near the pit, and on many corpses we could see mortal wounds made with knives on chests, backs and necks (see photo 13).

[11] A memorial plaque, erected at Slana in 1975, commemorating "the innocent Serbs, Jews and Croats" killed there, has been destroyed multiple times after Croatia's independence in the 1990s.