That’s super interesting! Here’s another fun bit of trivia:

In late May and June 1945, when the Yugoslav army started emptying its prison camps in Slovenia, prisoners from the Teharje camp and the Stari Pisker prison were brought by trucks at night to the abandoned Barbara Pit mine in Huda Jama. Slovene home guard POWs that were singled out in Slovene Gradhec, Velenje, Kranj, and Celje I were the first ones to arrive on the last week of May. NDH troops were brought on foot. Once arrived, groups of 5-6 prisoners with hands tied with wire were stripped, ordered to kneel above a mine shaft and shot in the head, or were hit with a mine hammer or pickaxe. In some cases, groups of 20-30 prisoners were tossed into a mine shaft, followed by hand grenades to finish off the victims. A number of prisoners were thrown in alive. Once the shafts were filled with corpses, the remaining prisoners were sent in the direction of Zagorje in northwest Croatia where they were killed, while the bodies were covered with lime to speed up decomposition. The mine what then enclosed with 400 metres of concrete and wooden barriers. Those still conscious tried to climb over each other to rematch the hatch, but could not escape the sealed mine.