The three theories explaining how the pyramids were built

Stonehenge is one of the world's most studied prehistoric sites and was built around the same time as the Great Pyramid of Egypt.

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.

Scholars argue Egypt's Great Sphinx depicts the pharaoh Khufu

Egypt's ancient marvel, the 66-foot, 4,500-year-old Great Sphinx, is believed to stand as a guard to the great Giza pyramids—or tombs—of pharaohs Khafre and Khufu. Archaeologists have long debated which of the two leaders' faces is on the great monument, the father (Khufu) or the son (Khafre).

The Maya built their cities with advanced engineering

Maya cities featured pyramids, palaces, causeways, ball courts, and water-management systems that were engineered to support large populations—often tens of thousands—without the use of metal tools, draft animals, or wheeled transport.

The ancient engineers inspiring modern building practices

Modern concrete structures need replacing every 50 to 100 years, so why are buildings by the Maya, ancient Rome, and ancient China still standing strong? This article details how scientists are looking into humanity's past for clues on how to craft long-lasting structures. Part of the problem is adopting old material recipes to hold up to modern demands.

Stonehenge has produced wild origin stories

Built before the wheel was invented, Stonehenge inspired increasingly fantastical explanations—from a 12th-century tale of Merlin and Nephilim giants to 1960s claims that aliens built it alongside the pyramids.

Aliens have invaded ancient history

Avid fans of archaeology can sometimes fall prey to unsubstantiated claims like "aliens built the pyramids," provocative, dubious theories which fall under the category of pseudo-archaeology. Many of these claims are premised on hidden biases toward non-Western cultural heritages. This professor explores the hidden contours of pseudo-archaeology in this 12-minute TED talk.

Why only one of the seven wonders of the ancient world still exists

Greek writers recorded lists of great structures that were later codified by Renaissance writers. The definitive list includes the Colossus of Rhodes, the Giza Pyramid (the only existing one today), the Hanging Gardens of Babylon, the Temple of Artemis at Ephesus, the Statue of Zeus at Olympia, the Mausoleum at Halicarnassus, and the Lighthouse of Alexandria.

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.

See the major Egyptian monuments in high definition.

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.

Why are ancient ruins underground?

When cities fall into disrepair, it's often easier to flatten what you can and build on top. This is why modern archaeologists frequently discover ruins underground, revealing generational layers of cities rebuilt over time. This video explores major examples of this principle, from ancient Troy to even modern Seattle.

Why Water Towers Are Built This Way

The ancient Egyptians built prototypes of the modern Suez Canal

The idea to facilitate trade between the Mediterranean Sea and the Red Sea and connect the Eurasian continent was apparent even to pharaohs in the second millennium BCE. Though no physical traces remain, contemporary accounts attest to early, shorter versions of the canal, including from Herodotus.

Explore the major archaeological sites of Egypt's 3,000-year history.

Stonehenge was built using giant wooden rollers and precisely carved tongue-and-groove joints to lock the stones in place.

This short animation shows how human beings managed to lug 30-ton stones over miles of prehistoric English countryside and stand them up The Stone Age engineering involved using giant wooden rollers and carving precisely interlocking tongue-and-groove joints to hold the heavy stones in place.

In 2017, a hidden chamber was found in the Great Pyramid of Giza by measuring particles created in the collisions between cosmic rays and atmospheric particles.

The unsolved mysteries of Machu Picchu

Who lived there? How did they get all that granite up there? Who were the 100 bodies found buried here, and why did some of them have elongated heads? Explore eight of Machu Picchu’s unanswered questions while scrolling through panoramic, clickable street-view images of the site, in this guide from Google Arts and Culture.

New scientific tools, such as radiocarbon dating and DNA analysis, have transformed what we know about who built Stonehenge.

Techniques such as radiocarbon dating, DNA analysis, and isotopic testing have revised scholars' understanding of Stonehenge. This article presents evidence suggesting that societies were more cooperative and less violent than earlier theories had suggested.

Examine a 3D model of the Rosetta Stone

One of the most famous archaeological finds of all time, the 1799 discovery of the Rosetta Stone helped unlock the secrets of ancient Egypt. Inscribed on the granite slab was the same passage in three languages: hieroglyphics, Old Egyptian, and Greek, which enabled scholars to decode the ancient language. Take an up-close look with this 3D model made up of more than 200 composite photos.

Inside Saqqara, ancient Egypt's sprawling necropolis outside Memphis

Located 20 miles south of modern-day Cairo, the 4-square-mile site contains the oldest known stone complex in the world, the venue for royal tombs and monuments for one of the earliest Egyptian capitals, Memphis.

Earth's total mass is equivalent to 13 quadrillion Egyptian pyramids of Khafre

Newton's law of universal gravitation was used to calculate the value after Henry Cavendish torsion balance experiments determined the missing value of the universal gravitational constant from Newton's equation.

The essential facts to know about ancient Egypt

Ancient Egypt spanned three millennia—more than 10 times the history of the US—but disappeared from the world's consciousness until the 18th century when it was rediscovered by Napoleon's army. Take a trip through the dynastic periods in this three-minute video.

Go inside Queen Meresankh III's tomb

Examine art, explore the structure, and let yourself be transported back 3,000 years to when the granddaughter of the Pharaoh Khufu was buried. The site, first discovered in 1927, is known as a unique underground chapel with preserved depictions of the daily life of ancient Egyptian royals, and features one of the earliest known canopic jars, vessels used to store the organs of mummified individuals.

How did the Inca build Machu Picchu?

How did the Inca, a people without iron or steel, build a city that has withstood hundreds of years of earthquakes and inclement weather? Machu Picchu stands atop steep landslide prone slopes and active fault lines and gets up to 80 inches of rain...

Fascinating 3D animation shows how Romans built roads

Highly efficient engineering and materials production allowed Roman administrators to lay down nearly 50,000 miles of roads across the ancient empire. These roads were built so effectively that many are still around today. Watch this quick 3-minute video to see how they did it.

In 1822, French scholar Jean-François Champollion deciphered Egyptian hieroglyphs using the Rosetta Stone.

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.

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.

To reach the afterlife, Egyptians lived in accordance with ma'at, or harmony

The ancient Egyptians held many beliefs about eternal life, fueling entire industries tasked with building tombs for the dead. Their leader, the pharaoh, was believed to be divine, and the lives of ordinary people were punctuated with ritual and myth. Learn more about their religion here.

Go inside the Washington Monument

This video tour of the Washington Monument explores its interior, construction delays, political battles, memorial stones, earthquake damage, and later modernization—showing how symbolism, engineering, and 19th-century politics shaped the nation's tallest monument.

Ancient Romans sometimes lobbed insults through graffiti

Graffiti was used to communicate ideas, offer advice, and, not unlike the internet, talk some trash. That was especially true with tourists, who sometimes scrawled messages on the pyramids, including one person who complained, "I can not read the hierogylphics." In response, someone replied, "Why do you care that you can not read the hieroglyphics? I do not understand your concern."

Reconstructing an average day in ancient Egypt

Egyptologists can reconstruct the intimate details of everyday life in the ancient civilization by studying the archaeological material preserved in tombs, monuments, and partially intact neighborhood layouts. Watch a comprehensive tour of the daily habits and lifestyles of ancient Egyptians with expert Dr. Joann Fletcher.

Engineering tall structures requires managing wind, earthquakes, and other destabilizing factors

Reinforced concrete, energy dampers, braced frames, flexible structures, and aerodynamic decks were among the methods implemented when building structures such as the Shanghai Tower, the Texas Super Skyscraper, and the South Rangitīkei Viaduct.

Structures from ancient Rome have endured for millennia because tiny pieces of lime in Roman concrete enabled it to self-heal and prevent cracks from spreading when exposed to water.

Explore the Valley of the Kings

The ruins of ancient Egypt are so widely dispersed throughout the Nile River Valley it can be hard to keep track of everything. The Theban mapping project from the American Research Center in Egypt provides beautiful interactive explorations of dozens of sites along the Valley of the Kings, which served as the necropolis for New Kingdom royalty.

The Ishango bone suggests mathematics was born about 20,000 years ago

Ancient civilizations developed mathematical systems for various purposes, including the Egyptians for the construction of the pyramids and the Ancient Greeks for logical reasoning in theorems. However, these systems were predated by the Ishango bone—found in the Democratic Republic of the Congo—whose notches suggest a base ten system, prime numbers, and simple mathematical operations.

Researchers once thought Stonehenge functioned as a precise astronomical computer

In the 1960s, scientists used early computers to analyze the stone layout at Stonehenge, arguing it could predict eclipses and other celestial events. This BBC Sky at Night Magazine piece explains how the theory arose—and why scholars now doubt it.

Egypt's pantheon is the result of a thousand years of myths

Their pantheon consisted of nearly 2,000 divine beings which evolved over time, led by the broadly worshipped sun god Ra. Many of the myths surrounding each god changed dramatically or even intertwined with others as cult followings grew popular or shifted from city to city.

The unbuilt monuments of Washington, DC

The capital city of the United States famously was built in a swampy area, with dozens of memorials, monuments, and more spanning its vast and complex design. This video explores five monuments that were either built or were rejected as alternatives in the sprawling District of Columbia on the banks of the Potomac River.

What Stonehenge sounded like

Researchers built the first scale model of the world's best-known prehistoric stone circle, Stonehenge, to study its acoustic properties. Built approximately 5,000 years ago, the landmark in southern England has puzzled historians for centuries, but...

The Washington Monument was completed in 1884 after nearly 40 years of delays and funding shortages

At the time of its completion, the Washington Monument stood as the tallest building in the world. Its construction stalled for decades due to political disagreements and the Civil War. The 555-foot obelisk cost nearly $1.2M to build (around $40M in today's dollars).

Ancient Egypt began as a collection of independent city-states along the Nile

Those cities were gradually organized into Upper and Lower Egypt, names derived from the northern flow of the river. The region was unified for the first time in 3,100 BCE under King Menes (also known as Narmer).

See ten of the most amazing Mayan ruins

Hidden beneath the jungles of Mexico’s Yucatán Peninsula, Maya temples, pyramids, and cities reveal the civilization’s vast construction ambitions. Decades of archaeology have uncovered these sites, which are explored in detail in this guided video tour of 10 significant ruins.

Explore the world's most famous leaning towers and structures

Pisa gets all the fame, but the quirk of a tilt adds precarious charm to dozens of famous buildings around the world. There are Pisa replicas, but also old castle towers, crooked houses and tilted churches and mosques.

Greek-Egyptian scientist Heron invented automatic doors for a temple

The doors opened when a fire was lit in front of the temple, causing heat and pressure to build in a nearby vessel that would force its contents into a higher secondary vessel. This secondary vessel would lower, pulling the doors open. When the fire extinguished, the pressure and liquid in the vessel would reverse course, closing the temple doors.

The high-tech mechanisms of the Roman Colosseum

The Roman Colosseum is one of the most iconic amphitheaters in the world and still partially stands today. Aside from its sheer size, the arena was equipped with some of the most high-tech engineering from the classical world, including sophisticated lifts, a huge retractable awning, and an underground network of tunnels, elevators, and trapdoors.

Infrastructure projects in New York are much more difficult today

The Erie Canal was one of the most ambitious infrastructure projects in American history. Many have said such an effort would be impossible today. This article explores why that is the case and ponders the future of large-scale American infrastructure development.

As of 2024, about 77% of the world's gold reserves have been mined

About 216 million metric tons—about 0.4% of the Great Pyramid of Giza's volume—have been extracted and used primarily for jewelry. The remaining reserves are estimated based on chemical analysis of rock samples extrapolated to the entire mass of Earth's crust.

Ancient Egyptians played Senet, a board game where players threw sticks or bones as dice.