The unsolved mysteries of Machu Picchu

Scientists are still confused how Machu Picchu was built

Machu Picchu, the 15th-century Inca city high in the Andes, continues to fascinate experts with its mysteries. The methods used to transport and carve its massive stones—some weighing 15 tons—remain unclear. Theories range from hundreds of men dragging the stones to innovative techniques like using expanding wet wooden wedges for precision carving.

Machu Picchu before it was a tourist attraction

The Machu Picchu we know today is familiar thanks to its neatly manicured plazas, lovingly preserved stone buildings, and ever-present hordes of tourists. But that’s not what Hiram Bingham saw when Melchor Arteaga led him to the site in 1911. Back then, it lay covered by centuries of tropical overgrowth.

Machu Picchu, 101

Machu Picchu was built right on top of two intersecting fault lines, which makes it even more baffling how its temples and terraces have survived for more than 500 years—especially since no mortar was used to hold the precisely cut stones together. As this three-minute NatGeo video explains, this ingenious construction method allows the stones to bounce in place when earthquakes hit, shaking and rattling but rarely collapsing.

Meet Pachacuti, the king who built Machu Picchu

In the 1400s, King Pachacuti of the Inca Empire wanted a summer resort for himself, his family, and his entourage. So he and his builders set out to build Machu Picchu, a feat of engineering, carving, construction, and more. Its 700 terraces remain intact today, while its trapezoidal stones inspire construction efforts around the world. Learn about the fascinating process of building this wonder of the world here.

Mapping tourism at Machu Picchu

Only 750 people lived at Machu Picchu at its height, but today, almost ten times that number trample through its delicate plazas and agricultural terraces every day. This data visualization vividly illustrates the skyrocketing numbers of visitors to Machu Picchu over the decades, and highlights the risks of over tourism, including soil erosion and other environmental threats, and negative social and economic impacts.

A virtual reality experience of Machu Picchu

If you can’t make it to the Andes, this virtual-reality experience—created using 360-degree cameras, and 3D modeling and sound design—is the next best thing. It lets you explore all the site’s major landmarks, including the Sun Temple and the Temple of the Condor, while listening to the sound of the wind whipping through the ruins, birdsong, and audio commentaries from expert guides.

The original article revealing Machu Picchu to the world

After first coming upon the ruins of Machu Picchu in 1911, Hiram Bingham’s subsequent expeditions were funded by Yale University, the Peruvian government, and $10,000 from a then-young National Geographic Society—in fact, it was the first archaeological grant that NatGeo ever issued. The magazine devoted its entire April 1913 issue, all 192 pages, to Bingham and his findings. You can read that issue in its entirety here.

Machu Picchu, sacred backdrop for your dating app pic

Anyone who’s been on Tinder or Hinge in the last decade has noticed it: the obligatory Machu Picchu selfie, almost as ubiquitous as those photos of men posing with a fresh-caught fish. How did Machu Picchu, of all places, become a dating-app cliche? This satirical essay from McSweeney’s doesn’t answer that question, but has a great time poking fun at it.

Rediscovering the Inca Empire

In 1991, anthropologist Johan Reinhard was trekking up the snowy face of a dormant volcano when he came face to face with the mummified remains of a teenager who had been sacrificed to the Incan gods centuries earlier. The story of “Juanita the Ice Maiden” is just one of the riveting tales featured in this four-part series from the popular podcast "History Hit".

A gallery of places without addresses on Google Street View

Google Street View records billions of images of streets across the world. Within those photos are many "unplaces," locations that appear to have some purpose or former history but do not have an address. This site curates some of those images and seeks further information from users. You can peruse the odd, fascinating locations spread across both rural and urban areas.

A history of China's ancient hidden tombs

Like many ancient cultures, the Chinese had a tradition of burying the dead in elaborate tombs, which would serve as both burial places and residences for the deceased. Archaeological evidence of these tombs, including those of former emperors, provides insights into the country's cultural evolution.

Explore the archaeological treasures of Pompeii, the city buried under volcanic ash when Mount Vesuvius erupted in 79 CE.

How 'the Iceman' got his tattoos remains a mystery

Ötzi the Iceman, discovered in 1991, is one of the oldest human mummies ever found—and his 61 tattoos remain a mystery. This explainer looks at how researchers believe the tattoos were made, what their placement suggests about ancient medicine and culture, and why we’re still piecing together their true purpose today.

The hidden hallway behind Mount Rushmore and why it’s unfinished

Mount Rushmore was designed to be more than a massive monument to US presidents, and its ambitious plans were part of the reason why. This fascinating video explores its backstory, creation, and the hidden tunnel behind President Lincoln's head.

See haunting images of the plaster casts of Pompeii’s victims

The plaster casts preserve victims’ final moments in striking detail—from their poses to the expressions frozen on their faces. This piece explains how 19th-century archaeologist Giuseppe Fiorelli devised the method long after the bodies had decomposed.

What it's like to go inside the Great Pyramid of Giza

Tourists can actually enter the ancient wonder, taking a 15-minute jaunt through tight spaces some describe as uncomfortable. The focal point of the journey is the chamber of the dead pharaoh, historically significant but not always visually compelling. The author describes it as a cool bucket list item but wouldn't repeat it.

Explaining the icy mystery of the Dyatlov Pass deaths

A decades-old mystery from Soviet Russia could be explained by studying the science of snow. After nine students died on a hiking trip in the Ural Mountains, Soviet investigators found six had perished from hypothermia while three others died from blunt force trauma. The mystery confounded officials for years, and rumors of yeti attacks and similar theories abounded until researchers proposed a new potential culprit: an avalanche.

What we know about the mysterious colossal squid

The colossal squid, the world's largest invertebrate, remained hidden from human discovery until nearly a century ago. Explore the world of the enormous and mysterious creature, including its features, habitat, and scientific significance. You can even plan a visit to the Museum of New Zealand Te Papa Tongarewa and marvel at a real-life display.

See a 3D reconstruction of Tenochtitlan, the Aztec capital that was home to an estimated population of 200,000 to 400,000.

What were the Aztecs really like?

Does the society live up to its blood-thirsty stereotype? Archaeologist Eduardo Matos Moctezuma answers this question and more in this short article. Moctezuma was the principal excavator of the major Aztec archaeological site Templo Mayor in the 1970s. He shares how the culture grew from a combined emphasis on war and agriculture, and ruled one of the world's largest cities at the time.

Explore the Museum of the World

This collaboration between the British Museum and Google presents an interactive timeline showing artifacts from five world regions. Go back in time and learn about each item from the museum.

Driving the 99 bends up China's Tianmen Mountain Big Gate

A huge rock gate sits atop a mountain in China's northwestern province of Hunan, where visitors climb 999 stairs to crest the natural wonder. For years, tourists used a cable car to reach the top, but a thrilling, curvy road was built in recent decades to allow for better access—and has become an attraction in itself.

The mysterious qualities of obsidian and magnetite

Obsidian is a dark volcanic glass created when lava cools quickly and frequently contains magnetite, a key early mineral used in compasses. Large deposits were discovered and used in central Mexico by the Toltecs roughly 1,000 years ago at the ancient site of Teotihuacan. This essay explores obsidian's cultural impact and the mysterious presence of magnetite in migratory birds.

The Paranthropus genus, our mysterious extinct cousins

In the last century, skull and jaw fragments have been discovered in East Africa suggesting an ancient hominin species lived, evolved, and died alongside humanity's ancestors. With large, broad skulls and strong jaws, the Paranthropus genus—which includes several related species—is an absorbing case of the effects of niche partitioning, where species coexist by adapting differently to the environment. Paranthropus died out and human ancestors endured. Find out why here.

In 1963, a basement renovation in Turkey revealed a passageway to a hidden, multilevel underground city that once housed as many as 20,000 people

Mary Cassatt's mural from the 1893 World's Fair mysteriously disappeared

The massive mural was called "Modern Woman" and was displayed in the Woman's Building at the 1893 World's Columbian Exposition, better known as the Chicago World's Fair. When the fair closed in October of that year, the mural was put into storage, but it later went missing. It hasn't been located since. All that remains are black and white photos of it, like the one below.

A collection of ancient Mayan glyphs and pictographs

The Maya had a syllabic and pictorial writing style that featured many incredibly detailed glyphs. Click here to check out this ancient writing style (and maybe test out their related phonetic sounds).

Bad Ancient: a site to fact-check claims about the ancient world

Peruse popular questions about ancient Rome, Egypt, Greece, and more, from whether Greek boxers were ripped or to what extent Alexander the Great conquered the world.

Stanford built a Google Maps for the Roman Empire, revealing how much it cost to travel in the ancient world

See photos of Meteora, a mountainous site in central Greece, home to 14th-century monasteries perched atop soaring outcroppings.

In 2018, 26-year-old missionary John Allen Chau was killed by tribesmen after attempting to reach and evangelize on India's isolated North Sentinel Island

Explore an interactive map built from more than 100,000 survey responses on where people find joy in their lives

Apollo astronauts left items in the moon's 'toss zone,' including golf balls, family photos, and bags of human waste, to make room for lunar rocks.

When you complete a CAPTCHA on a website to prove you are human, you may be unknowingly training algorithms for self-driving cars, whose systems require training data to help identify crosswalks, bicycles, and other outdoor objects.

Against his wishes, Albert Einstein's brain was removed before his cremation, and the pathologist responsible stored it for decades in mason jars within a beer cooler.

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Read a deep dive on the 'all-purpose healing' peptide BPC-157.

The identity of the Tank Man in the iconic photo from the 1989 Tiananmen Square protests remains unknown and was possibly killed.

Hear about the 250-year history of the United States Postal Service, complete with some of its strangest deliveries, important innovations, and the figures that made it an American institution.

Take a 3D tour of the Hajj, Islam's annual pilgrimage to Mecca, undertaken by more than 1.5 million Muslims each year.

A 2019 Facebook event called on attendees to "Storm Area 51, They Can't Stop All of Us," resulting in countless memes, the creation of a music festival, and eventually the arrests of those who did try to approach the area.

In 2009, the nation was gripped by the story of a missing young boy who was believed to be floating over Colorado in a homemade balloon, until it was revealed that he was at home the whole time.

Frank Lloyd Wright's houses are historically hard to sell because they're old, subject to local landmark commissions, and often unfashionable

For centuries, Niagara Falls has been a magnet for daredevils seeking to conquer one of nature's most powerful wonders, with its 200-foot drop and water rushing at 32 feet per second with 280 tons of force.

Many legends about George Washington, including his supposed wooden teeth and the story of cutting down the cherry tree, lack evidence.

The first horror movie is believed to be George Méliès' 1986 short 'The Haunted Castle,' which pioneered the use of special effects

Apeirophobia is an overwhelming fear of living forever, perhaps stemming from the brain's inability to conceptualize an infinite life.

The US first hosted the World Cup in 1994, a tournament that lives in soccer infamy for its poor planning and the murder of Colombian player Andres Escobar, who'd accidentally scored on his own net.

See how fireworks are made and learn how metals like magnesium and copper are responsible for different colors.

Most of the observable universe's volume consists of voids and supervoids—enormous regions of space with little to no galaxies, stars, or light.