The evolution of Mexico City, from the Aztecs to today

See a 3D reconstruction of Tenochtitlan, the Aztec capital

Mexico City today stands atop Tenochtitlan, the Aztec Empire's capital, founded in the early 1300s. This resource offers detailed 3D models and multiple visual perspectives of the ancient city—displaying its canals, grid layout, temples, and broader Mesoamerican cultural context.

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

The Aztec Empire explained

Tenochtitlán grew into a powerful city-state supported by innovations such as chinampa farming and its central role in the Triple Alliance. Spanish forces later exploited internal rifts to overthrow the empire, but the city’s legacy endures in modern Mexico City’s historic core.

The Valley of Mexico sits over 7,000 feet above sea level

Once dominated by the shallow waters of Lake Texcoco, the high-altitude Valley of Mexico—surrounded by volcanic peaks—was home to the Aztec capital Tenochtitlan. This resource breaks down the region’s unique geography and why it became a cradle of Mesoamerican civilization.

See the path Spanish conquistadors took to conquer the Aztecs

Spanish expeditions reached central Mexico as the Aztec Empire was expanding its influence. After securing bases in the Caribbean, they advanced west into Aztec territory, triggering a cascading conflict depicted in this interactive map and timeline.

Teotihuacán was already ancient when the Aztecs encountered it

By the time the Mexica reached Teotihuacán, the vast city had been abandoned for centuries. First settled around 400 BCE, the inhabitants developed monumental temples, canals, and a carefully planned urban grid centered on the Avenue of the Dead.

Maya civilization explained

The Maya built vast jungle cities that could accommodate up to 50,000 people, developed advanced mathematics—including the concept of zero—and created one of the Americas’ earliest writing systems. Though many cities later declined, their scientific and cultural achievements continue to shape our understanding of the ancient world.

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.

A map of Barcelona from 150 BCE to 2010

Watch Barcelona evolve from Iberian settlements in 150 BCE to Spain’s second-largest city in the modern day by toggling this chronological series of 27 maps. Accompanied by a short contextual blurb, each map shows Barcelona’s steady urbanization over more than two millennia. For those captivated by the interactive, read this interview with one of the project’s key cartographers. He discusses how the mega-map was created and what it reveals about Barcelona’s history.

COVID-19 disruptions revived ancient chinampa farming in Mexico City

When the pandemic disrupted food supply chains, chinamperos—farmers who cultivate the Aztec-era “floating gardens” built atop shallow lakebeds—shifted to direct sales in the city, boosting their visibility and reconnecting residents with a longstanding local agricultural tradition.

Learn to speak the ancient Aztec language Nahuatl

Across the Aztec Empire, you'd be met with variants of Nahuatl, the indigenous language still spoken by approximately 1.5 million people today. This free, self-paced online university course teaches the Veracruz variant, beginning from the language's "piltlahcuiloltzitzin"—or alphabet—to how to conduct specific "tlamachtiliztli" or ceremonies.

The architectural evolution of New York City's Chinatown

Cityscapes continuously evolve, and each stage in their transformation tells a unique story. In Manhattan's Chinatown from the 1940s to today, the architecture has bloomed from an ethnic conclave for often mistreated migrants to a vibrant cultural hub today. See varying elevations and facades over time.

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.

A Native American city in present-day Illinois once rivaled the size of medieval London

Around 1100, the city of Cahokia, the largest Mississippian settlement, reached a population of 15,000 to 20,000. Located across the Mississippi River from present-day St. Louis, it featured massive earthen pyramids and a central plaza the size of 35 football fields.

Learn how Mexico’s anti-slavery stance shaped the US–Texas conflict

Historian Alice Baumgartner explores how Mexico’s abolition of slavery clashed with Anglo settlers' ambitions in Texas. The episode reveals how enslaved people fled south to freedom, reshaping the politics that led to Texas independence and the Mexican-American War.

Making sense of Mexico City's traffic honks and horns

A car's horn makes just one sound, but somehow, drivers across the world manage to use the monotone for a surprising variety of purposes. This audio-inflected essay takes readers into the nuanced horns of Mexico City's famously congested traffic, providing a "claxonomy" (taxonomy + claxones, or horns) of its drivers' honks.

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.

Athletes in Mexico are reviving a 3,000-year-old sacred sport

A modern team is working to revive Juego de Pelota, an ancient Mesoamerican team sport played by the Maya, Aztecs, and neighboring cultures. Once central to ritual and community life, the game was outlawed by Spanish conquistadors in the 16th century.

The holiday has evolved alongside its participants' cultural identities

The Day of the Dead blends various traditions, including Aztec myth, Mexican heritage and Chicano identity. That makes for a complex and evolving holiday. This conversation between Cynthia Vidaurri, a Smithsonian folklorist, and Lalo Alcaraz, a cultural consultant for “Coco,” analyzes how the varied influences have created the modern holiday.

The history of the Met

From a single sarcophagus to a collection of more than a million artifacts that span nearly the entirety of human civilization, the Met and its importance have grown significantly over the last 150 years. This history of the museum hits all the highlights, including important acquisitions, new wings and galleries, and the importance of the buildings that hold and display all of the incredible artwork.

How LA brought water to its booming population

By the turn of the 20th century, Los Angeles had grown from a dusty, crime-ridden pueblo into a thriving metropolis. The only problem was that it was growing too fast. Here's the story of how the booming town created a massive water infrastructure to redirect area rivers to its residents.

Tokyo is the world's largest city by population

Home to over 41 million people, the megacity used to be a humble fishing village called Edo. Since Japan opened to foreign trade in the mid-1800s, Tokyo has made significant economic advances and achieved numerous milestones in public transportation, urban planning and culture.

Investigating 'the city that kills women'

For nearly three decades, thousands of women have disappeared near Ciudad Juarez, Mexico. Some were mutilated in ways that led authorities to suggest it the work of a serial killer, some were trafficked into slavery, and others have never been found. Opening with a hail of bullets, this 10-part podcast series hopes to uncover those responsible for the femicides.

The Greek city of Alexandria in Egypt helped form the template for modern cities

It was designed by Dinocrates, who studied under Hippodamus, the father of urban planning. Hippodamus preached that urban planning should take into account function, culture, and politics. Dinocrates' design of Alexandria meant applying Hippodamus' teachings on a scale never before attempted.

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 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.

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

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

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

Graffiti dates back to at least ancient Pompeii, where citizens scrawled messages to one another on public walls

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.

Visualize the path of every solar eclipse from 1900 to 2099 and see what each looks like when observed from different locations on Earth.

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

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

Waves off the coast of Nazaré, Portugal, can reach over 100 feet and are caused by the area's deep underwater canyon geography

Volcanoes 'die' when their supply of magma runs out, if they are shifted away from their underlying magma reservoir, or if they get clogged by collapsing or their magma cooling back into rock.

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.

View the ten deadliest tornadoes in US history.

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

Tattoos remain visible on your skin thanks to immune cells called macrophages

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

Memecoins are a type of cryptocurrency—a form of digital currency with a wide variety of uses—created around popular 'memes,' or viral internet jokes.

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.

Crows are believed to have intelligence on par with a seven-year-old child and demonstrate complex behaviors, from problem-solving with tools to recognizing human faces.

The US Constitution is widely regarded as the longest-standing written national constitution still in force—see how it has influenced rights worldwide.

Some researchers have labeled nomophobia, the fear of being without your phone, as 'the phobia of the 21st century.'

The word 'jazz' evolved from 'jasm,' 19th-century American slang for 'energy'

Watch contemporary footage covering the US-backed Shah of Iran fleeing the country in the face of the 1979 Iranian Revolution

The Dracula character, now seen as the vampire archetype, was inspired by a seafood-induced nightmare its creator experienced.

See the evolution of Ebola vaccine and treatment development.