Polajna is the site of two known mass graves from the end of the Second World War. They contain the remains of an unknown number of Croatian soldiers and civilians that were disarmed and then murdered at the end of the war. Most of the victims were murdered in the mine, but a smaller group was murdered at the tailings dump. The Polajna Mine Mass Grave (Slovene: Grobišče rudnik Polajna), also known as the Hasenbichl Mine Mass Grave (Grobišče Hasenbichlov rudnik), is located on a slope north of the houses at Polajna no. 10. It is an abandoned mine shaft. The Mine Tailings Mass Grave (Grobišče pod rudniško jalovino) is located south of the settlement, 60 m from the house at Poljana no. 1.