What was the Great Inca Road?

What was it like to rebel against the Inca Empire?

The Inca Empire grew to its gargantuan size and became the largest empire in ancient Americas through conquest, annexation, and arranged marriage, approaches that didn't always go over well with locals. Watch this five-minute video to experience a...

The Inca Empire: a timeline

When did the Inca Empire solidify into an empire? When was it invaded by the Spanish? What remains of it today? Click through this timeline to learn more.

How the great city of Cusco came to be, according to the Inca

The chronicler Inka Garcilaso de la Vega recorded the origin story of the Inka (also spelled Inca) and the founding of Cusco, the capital of the society's great empire. Listen to the Inca origin story in this 4-minute video narrated by a child.

The decline of the Inca Empire

The Inca Empire was awash with gold, and the Spanish knew it. So what happened next? Read this BBC article to learn what happened during the last days of the Inca Empire.

Inca trail interactive map

Machu Picchu gets all the attention, but it’s definitely not the only Inca ruin in the area. Some dedicated trekkers opt to see the sites through a multi-day hike down the Inca Trail, which spans 26 miles from the Sacred Valley to Machu Picchu and reaches elevations as high as 13,800 feet above sea level. This 3D tour gives a sneak-preview of the ruins along the route, and the intense topography.

Machu Picchu explained

High in the Andes Mountains, Machu Picchu stands as a testament to the ingenuity and resilience of the Inca Empire. Constructed in the mid-15th century during Emperor Pachacuti’s reign, this site is believed to have served as a royal retreat or ceremonial center. Its engineering marvels, including sophisticated aqueducts, terraced farming systems, and precisely carved stone structures like the Sun Temple, highlight the advanced skills of the Inca civilization.

How the Inca used threads to communicate

One of the great mysteries of ancient Peru is that the Inca did not have a system of writing, but communicated with a system of strings tied with knots. This 4-minute video explores its possible uses.

Roman roads have lasted for millennia and were key to its military might

Known for their almost absurd straightness, Roman roads connected the empire's armies, messengers, and traders as imperial administrators sought to keep down rebellion and build up Roman wealth. Rome's highways were expertly engineered, well-patrolled, and easy to navigate.

Why did the Spanish steal the Inca's mummies?

From inside stone palaces and atop sacred mountaintops, the Inca dead continued to wield incredible power over the living. So much so that the Spanish confiscated them. Read more about the afterlife of these mummies here.

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".

What llama beans can tell us about the Inca Empire

Fun fact: Llama bean is just another term for llama poop. Another fun fact: Scientists are using these beans and related microorganisms to learn more about the Inca Empire. Read this article to learn how.

Inti, the Sun God of the Inca

The Incas were polytheistic, worshiping many gods, but Inti was the most powerful one in the pantheon. He was the god of the sun and also ruled over agriculture, fertility, and war. Inti was mainly a benevolent deity, though the Inca believed that solar eclipses meant Inti wasn’t pleased. To appease him, the Inca gave sacrificial offerings including food, white llamas, and even human beings.

The last Inca grass suspension bridge in Peru

High in the Peruvian Andes, the aging Q’eswachaka bridge sags precariously over the Apurímac River. It has been built and rebuilt continuously for five centuries. Read more about it here.

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

The century of the Panama Canal

The Panama Canal connects the Atlantic and Pacific Oceans through a 51-mile route that transformed global shipping when it opened in 1914. This breakdown covers how it was built, the workers behind its construction, and why its future may be challenged by climate and competition.

The Gold Road: how the medieval empires of West Africa traded across the Sahara

Throughout the Middle Ages, the West African empires of Ghana, Mali, and Songhai moved valuables across the Sahara and as far north as France using the Gold Road. This route enabled the trade of gold, ceramics, manuscripts, ivory, religion, and...

The Mississippian culture mastered corn cultivation, long-distance trade, and complex governance

From roughly 1100 to 1540, Mississippian peoples across what is now the Southeastern United States mastered corn cultivation, built political structures that organized large populations, and maintained trade networks that spanned much of the continent.

The 52-mile marvel of engineering inside Glacier National Park

Glacier National Park is home to over one million acres of natural beauty, but it also includes 52 miles of a manmade miracle in Going-to-the-Sun Road, which takes drivers on a majestic tour through some of the park's most breathtaking views. This brief history and photo gallery allows you to gain an appreciation for the incredible engineering behind the road’s construction.

How the US built the Interstate Highway system

As late as World War II, it took a well-prepared motorist roughly 10 days to cross America from coast to coast in a car. That all changed when the nation undertook its biggest public infrastructure project in 1956, the National Interstate and Defense Highways Act, initiating a 36-year, $114B mission to lay 41,000 miles of roads across America. Watch a smart overview here.

A trading company became Britain's most powerful imperial force

The East India Company began as a private merchant venture and grew into Britain’s dominant power in India—amassing wealth, fielding armies, and governing tens of millions until the Crown took direct control in 1858.

Explaining the rich heritage of the ancient Greeks

Though only a unified empire for a decade under Alexander the Great, the ancient Greeks left lasting cultural influence throughout the modern world. Curious about ancient Greece? 1440's got your breakdown of the ancient civilization.

The history of the British Empire—all in a single take

This video delivers a rapid, rhyming walk-through of the British Empire—filmed in one continuous shot aboard a sailing ship and featuring costumed actors portraying figures from Sir Francis Drake to Pocahontas.

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

Decoding the Indus Valley script

About 100 years ago, archaeologists uncovered an ancient city along the bank of the Indus River in eastern Pakistan that dated back to 2,500 BCE, though its urban planning, grid-like roads, brick-lined streets, multi-story homes, and sanitation and...

A primer on reading the rock layers of roadcuts

Road construction often requires cutting through layers of rocks, coincidentally exposing millions of years of rock formation. This simple guide introduces basic rock types, what causes curves and folds, and the major rock formations in regions around the US.

Step inside Colombia’s most powerful drug trafficking group

The AGC is Colombia’s most powerful drug trafficking organization. Founded by a paramilitary leader who dismissed the Colombian peace process, the AGC stands for the Gaitanist Self-Defense Forces of Colombia. Self-described as “an army fighting...

Who was Ferdinand Magellan, and what did he do?

Portuguese explorer Ferdinand Magellan left Spain on a trip to gather spices and circumnavigate the globe with five ships, more than 250 men, outdated maps, and a profound misunderstanding of the Pacific Ocean's width. Hear from a historian on...

Explore an interactive map of battles from the American Revolution, along with detailed summaries of each engagement

The American cockroach is actually from Africa, an apparent hitchhiker aboard ships carrying enslaved people, with evidence suggesting the bug may have arrived in the New World as early as the 1600s.

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.

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

The power and influence of the American presidency have expanded significantly over time—far beyond what the founders envisioned.

Explore the history, structure, and species of Australia's Great Barrier Reef with this interactive journey narrated by Sir David Attenborough.

The American Society of Civil Engineers' infrastructure report card gave the US a C in 2025, its highest grade since the project launched in 1998.

While El Niño moves warm Pacific Ocean waters east along the equator, La Niña moves them west, shifting where rainfall will become more common for months.

The syncytiotrophoblast is the outer layer of the placenta and the largest human cell, spanning an area about twice that of a king-sized bedsheet.

After NASA's Voyager 1 captured Earth as a single pixel as it left the solar system in 1990, astronomer Carl Sagan used the image to reflect on humanity's fragility and the responsibility to protect 'the only world we've ever known.'

Electrical grids worldwide must double their power delivery capacity by 2050 to meet surging demand from AI and electric vehicles.

How Amazon operates a 'flywheel' business model, a self-reinforcing cycle that drives continuous growth

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.

'Grand Canyon of the Yellowstone,' a work by American painter Thomas Moran, inspired Congress to establish Yellowstone National Park.

A researcher recently discovered an interview from 1967 between groundbreaking journalist Joan Didion and the Grateful Dead, years before the band became an institution.

For centuries, it was common to sleep in two shifts: a few hours at the beginning of the night, and a longer period beginning around midnight

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

The term 'algorithm' originated from the Latinized name of al-Khwārizmī, a 9th-century mathematician whose works introduced Arabic numerals and the decimal-based numeral system to Europe and whose treatise 'Al-Jabr' gave algebra its name.

Explore a list of the 100 best novels of all time, compiled by some of the world's best living writers, including Salman Rushdie, Stephen King, and Jennifer Egan.

Abraham Lincoln was almost assassinated weeks before his inauguration as he traveled from Illinois to DC through Baltimore in 1861; it took two independent claims for Lincoln to be convinced the threat was real

Some coin denominations have ridges etched on their sides, partly to prevent counterfeiting, in a practice called 'reeding.'

The deadliest aspect of volcanic eruptions is often not lava, but pyroclastic flows—avalanches of ash, gas, and rock that can move more than half the speed of sound.

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