The quintessential national play of Mongolia is the Secret History of the Mongols, which we already talked about in a previous article. Its author is unknown, but it is known that it was composed between 1227 and 1228, shortly after the death of Genghis Khan.
The original document is not preserved, but a copy a century later and written in Chinese characters from translations made by the Ming dynasty. It hardly says anything about the death of Genghis while he was hunting:
fell from his horse, and with great pain, died […] and in the year of the Pig ascended to heaven
Secret History of the Mongols

Genghis’s death occurred on August 18, 1227 during the capture of Yinchuan, in northern China and the former capital of the Western Xia Empire. Apart from what the Mongol history itself says, other later versions state that he died in combat, and Marco Polo indicates that the cause was an infection caused by an arrow:
I can tell you that Genghis Khan reigned six years after this battle, continually engaged in conquest, and seizing many provinces, cities, and fortresses. But at the end of those six years he went against a certain castle called Caaju, and there he was shot with an arrow in the knee, so that he died of his wound. He was a great pity, for he was a brave and wise man
Marco Polo, Milione (The Travels of Marco Polo) either wonder book) ch.67

Years earlier, Genghis had expressed a wish to be buried unmarked in accordance with the traditions of his tribe. His body was taken to Mongolia and buried somewhere near the Onon River and Burkhan Khaldun Mountain in the northwest of the country, his birthplace.
According to legend, the funeral escort killed anyone in their path, the slaves who built the tomb were killed, and finally the soldiers who had killed the slaves met the same fate. All in order to hide the resting place of the Khan.
According to tradition, all the great khans are buried around the tomb of Genghis, or at least in the same area, since its exact location has always been a mystery. Marco Polo states in this sense that, by the end of the 13th century, the Mongols were unaware of its location (if they had ever known it).
The area in question where tradition places the tomb is about 240 square kilometers and is located in the surroundings of the Burkhan Khaldun mountain, in the Khentii mountain range. It is one of the mountains that Genghis already designated as sacred, and today both the mountain and the surrounding sacred landscape They are part of the World Heritage Site designated by UNESCO and the Khan Khentii Strictly Protected Area.
But that area of 240 square kilometers has its own name, it is called Ikh Khorig (Great Taboo) and was sealed by the Mongols after the death of Genghis, punishing with death any intrusion.
It is not known for sure if Genghis is actually buried there, but the Mongols have taken great pains to give the impression that he is.
just the Darkhad access is allowed. It is a group descended from the ancient Mongol elite warriors, who were entrusted with the surveillance of the place. In the 2000 census there were about 16,000 people identified as darkhadbelonging to the 36th generation.
Even during the communist period of the country the area remained isolated, although for a different reason, since the Soviets feared that the figure of Genghis could encourage Mongolian nationalism.
It would not be until the late 1980s that the Mongolian government would allow the first archaeological excavations at the Great Taboo, which ended unsuccessfully. And it is that although the rest of the world has a great interest in finding the tomb of Genghis, due to the supposed treasures that it must house, the Mongols do not care.

National Geographic also tried it, using satellite images, without success. And a few years ago a similar project managed to identify 55 potential anomalies archaeological. In 2015 and 2016, two expeditions led by the French archaeologist Pierre-Henri Giscard, scientific director of the Institute of Deserts and Steppesanalyzed by drones a burial mound on top of the Burkhan Khaldun.
The analysis of the images shows, according to Giscard, that the burial mound is 250 meters long, is of human origin and seems to be based on the model of the Chinese imperial tombs of Xi’an.
But none of this can be confirmed, because the Great Taboo remains strictly closed.

Sources
Guarding the Spirit of Our Ancestor, Genghis Khan / Why Genghis Khan’s tomb can’t be found / Crowdsourcing the Unknown: The Satellite Search for Genghis Khan. doi.org/10.1371/journal.pone.0114046/Wikipedia.