History is rife with lost treasures, from Aztec gold hidden during the Spanish conquest to the Ark of the Covenant, which vanished during the destruction of Jerusalem over 2,500 years ago. In his book, "The Museum of Lost Things: True Tales of Fabled Treasures, Legendary Cities, and Mythical Creatures That Vanished From History" (National Geographic Partners, LLC, 2026), writer Sam Kean examines all things lost to time.

In this excerpt from the book, he looks at how the tomb of Genghis Khan, arguably the most successful ruler in history, has remained hidden for nearly 800 years and counting.

If archaeologists could vote on which lost grave they'd most like to find, Genghis Khan's would likely appear near the top of the list — in part to fact-check the gruesome legends surrounding his burial.

He was born in Mongolia around 1162, and supposedly emerged from the womb clutching a clot of blood in his fist. By all rights, the boy — whose original name was Temüjin — should have died young. His father, a nobleman in their tribe, was poisoned by a rival tribe when Temüjin was nine, and greedy schemers within his own clan banished the boy's family to the empty steppes, expecting them to starve. Historical accounts describe Temüjin as overly sensitive, terrified of dogs and prone to crying.

But he grew up fast. Even before adolescence, he'd already been enslaved (he engineered his own escape) and killed his older half brother. As a young man he discovered that soldiering suited him, and he ruthlessly eliminated all potential rivals among other nomadic tribes, until he was crowned Genghis Khan — universal ruler — in 1206. His other nickname was the Disturber of the Universe. His warriors were bold and battle-tested, and when they stopped murdering each other and turned their attention outward, they proved unstoppable.

They favored blitzkrieg tactics, sweeping in on horses and bombarding the enemy with arrows. But they could be surprisingly patient, too, and perfected the art of siege warfare. One notorious siege involved the city of Merv, in what's now Turkmenistan. Merv was the Alexandria of its day: a desert oasis teeming with gardens and libraries, famous for its silks and refreshing melons.

The Mongols couldn't resist it, and when the terrified artists and merchants inside surrendered after just six days of siege, a massacre ensued. "It was a memorable day for shrieking and weeping," lamented one chronicle. After burning Merv for good measure, Genghis Khan ordered his troops to count the corpses. There were 700,000. Yet however crazy it sounds, life under Genghis Khan had its benefits. He allowed the conquered to worship whatever gods they liked, a rare example of religious tolerance. He introduced the idea of diplomatic immunity to facilitate negotiations, and outlawed torture during interrogations. He promoted free trade, and founded history's first international mail system.

Over time, his empire also spread key technologies like the compass, abacus, printing press, and paper currency, as well as key social programs like universal education for children. No one was more ruthless when conquering (ask Merv). But if the vanquished people picked up the pieces and swore fealty afterward, life generally improved under Mongol rule. Genghis Khan's realm stretched from Korea to the Caspian Sea, an area twice the size of the Roman Empire. (Under his successors, it grew to the size of Africa.) And he accomplished all this with an army of just 100,000 warriors — fewer people than some modern stadiums hold.

Historian Jack Weatherford summed up his achievements thus: "[Imagine] if the United States ... had been founded by one of its illiterate slaves, who, by the sheer force of personality, charisma, and determination, liberated America from foreign rule, united the people, created an alphabet, wrote the constitution, established universal religious freedom, invented a new system of warfare, [and] marched an army from Canada to Brazil." Alexander, Julius Caesar, Napoleon — they weren't fit to carry Genghis Khan's saddle. If anyone in history deserved a grand mausoleum, it was him.

Genghis Khan wanted the opposite. Despite all the blood they shed, the Mongols were oddly squeamish about discussing d-e-a-t-h, so beyond the year 1227, contemporary sources say little about how Genghis Khan died. As a result, rumors multiplied. One story claims he died after tumbling off a horse. Others have him struck down by lightning or an arrow to the knee during battle (at age 65, no less). One source swears he was trying to ravish a conquered queen who, anticipating the crime, concealed a blade inside her vagina that sliced lil' Genghis wide open.

Regardless of the truth, his longtime wife Yesui dressed his body in a white robe, wrapped it in white felt with sticks of fragrant sandalwood, and clasped the shroud shut with golden straps. What happened next is impossible to say for certain. But according to lore, Genghis Khan received probably the most outrageous funeral in history.

After his wife bound him in white, a thousand soldiers took off on horseback to bury him atop a mountain. This cortege quickly turned into a rampage. To conceal their destination, the troops reportedly slaughtered every person they encountered on the 40-day journey, often with the cry "Go to the other world to serve our lord!" In some accounts, the soldiers killed every animal, too. Based on other Mongol burials, they likely interred him 20 yards deep, with the body oriented north-south and the head facing east. They probably tossed some treasures in — gilded saddles, gold rings, pearls wrapped in silk — along with slaves, concubines, and horses. (One tale has the soldiers burying a live baby camel with him, either so its bleating would serve as a funeral dirge, or so the grieving mother could lead them back to the site if necessary.)

After filling the grave, Genghis's soldiers either diverted a river to conceal it or trampled the ground with a thousand horses to obliterate all trace. Then they resumed the merry rampage on the return trip, butchering every unlucky hunter or merchant who wandered across their path. To their surprise, the thousand soldiers were themselves slaughtered when they reached home, as a further guarantee of secrecy — and then those slaughterers were also slaughtered, to make doubly sure.

Genghis Khan took privacy seriously. We have no idea how much of that is true. But it hasn't deterred the hunt for the grave. To the contrary: The elaborate concealment has made the pursuit all the more enticing. Four nations — Mongolia, China, Kazakhstan, and Russia — have claimed that Genghis Khan's bones lie within their borders. The strongest claim points to Burkhan Khaldun (God Mountain) in northeast Mongolia. Genghis Khan was born nearby, hunted there regularly, and worshipped the sky god Tengri there. He also once took refuge there while fleeing his enemies, and miraculously escaped. The mountain seemed charmed to him, and he'd mused during his life that it would make an ideal final resting place.

Strengthening the case for Burkhan Khaldun is the fact that later Mongol rulers proclaimed the land around the peak a forbidden zone and stationed a clan of ferocious guards there — the Darkhad, who murdered anyone who dared approach. (In exchange, the Darkhad paid no taxes and avoided compulsory military service.) Incredibly, the Darkhad kept this watch for 700 years, until the founding of the communist Mongolian People's Republic in 1924. The republic was a puppet state of the U.S.S.R., and Soviet leaders had a schizoid attitude toward the Disturber of the Universe. On the one hand, they admired his ruthlessness and gazed longingly at all the territory he'd gobbled up. On the other, they feared his memory would stir up nationalist sentiments in Mongolia and spur a revolt against the hated communists.

To forestall this, the Mongolian government banned the very mention of Genghis Khan's name. And to prevent Burkhan Khaldun from becoming a rallying point, officials fenced off a "highly restricted area" around the peak of 3,900 square miles (twice the size of Delaware), and parked a tank base at the site's entrance. The ban thawed somewhat after Joseph Stalin died in 1953, and one Mongolian official decided to celebrate the Disturber's 800th birthday in 1962 by putting him on a stamp. He overreached. Moscow ordered the man arrested, and he was chopped to bits with an axe. After the republic collapsed in 1992, the restricted area devolved into a nature reserve with some public access. But the land near Burkhan Khaldun remains daunting to explore. It's one of the most desolate places on Earth, with few roads and a population density down there with Greenland's.

Centuries of vegetation growth have choked off many areas, and the clear parts are prone to flash floods. Temperatures can swing from 100 degrees [Fahrenheit, or 38 degrees Celsius] in the summer to 50 below [minus 46 C] in the winter, so cold that even yaks drop dead. None of this has stopped Genghis Khan obsessives from searching out his grave. They've suffered snakebites and frostbite and been left stranded when their vehicles tumbled off cliffs. One man spent 40 years crossing and crisscrossing and re-crisscrossing the slopes and died without finding a thing.

In 2010, a few archaeologists tried a new approach. They posted satellite images of the Burkhan Khaldun region online and recruited volunteers to scour them for bumps, depressions, and other features that might indicate graves. Ten thousand people spent approximately 30,000 hours (3.4 collective years) poring over 2,300 square miles [5,950 square kilometers]. They flagged over a hundred spots worth checking out. While several proved inaccessible due to challenging terrain, 55 legitimate archaeological sites turned up among the rest, including megaliths, Bronze Age burial mounds, and an ancient city.

But there was zero trace of Genghis Khan. One archaeologist lamented that it was like looking for a needle in a haystack, except you don't know what the needle looks like. Call it Genghis Khan's final victory. The diverted river and trampling horses and the slaughter of all potential witnesses have succeeded in hiding him for most of a millennium now. His victims lay scattered across Eurasia, their skeletons long since ground to dust. But the bones of history's greatest warrior remain at peace.

Excerpted from The Museum of Lost Things by Sam Kean, published by National Geographic Partners, LLC. Copyright © 2026. All rights reserved.

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