On October 6, 2004, a joint Japanese-Mongolian archaeological dig uncovered what is believed to be Genghis Khan's palace in rural Mongolia, which raises the possibility of actually locating the ruler's long-lost burial site. Folklore says that a river was diverted over his grave to make it impossible to find (the same manner of burial as the Sumerian King Gilgamesh of Uruk and Atilla the Hun). Other tales state that his grave was stampeded over by many horses, and that trees were then planted over the site, and the permafrost also did its part in hiding the burial site.