Soviet troops entered the camp on 27 January 1945, a day commemorated since 2005 as International Holocaust Remembrance Day. In the decades after the war, survivors such as Primo Levi, Viktor Frankl, and Elie Wiesel wrote memoirs of their experiences, and the camp became a dominant symbol of the Holocaust. In 1947, Poland founded the Auschwitz-Birkenau State Museum on the site of Auschwitz I and II, and in 1979 it was named a World Heritage Site by UNESCO.