Genghis Khan (known in Mongolia as Chinggis Khaan) once ruled everything between the Pacific Ocean and the Caspian Sea. Upon his death he asked to be buried in secret. A grieving army carried his body home, killing anyone it met to hide the route. When the emperor was finally laid to rest, his soldiers rode 1,000 horses over his grave to destroy any remaining trace.

In the 800 years since Genghis Khan’s death, no-one has found his tomb.

Foreign-led expeditions have pursued the grave through historical texts, across the landscape and even from space ‒ National Geographic’s Valley of the Khans Project used satellite imagery in a mass hunt for the gravesite. But most interest in locating the tomb is international; Mongolians don’t want it found.

The reluctance is often romanticised by foreign media as a curse, a belief that the world will end if Genghis Khan’s tomb is discovered. This echoes the legend of Tamarlane, a 14th-Century Turkic-Mongolian king whose tomb was opened in 1941 by Soviet archaeologists. Immediately following the tomb’s disturbance, Nazi soldiers invaded the Soviet Union, launching World War II’s bloody Eastern Front. Superstitious people might call that cause and effect.

Folklore holds that Genghis Khan was buried on a peak in the Khentii Mountains called Burkhan Khaldun, roughly 160km north-east of Ulaanbaatar. He had hidden from enemies on that mountain as a young man and pledged to return there in death. (BBC)