The impressive walls of Constantinople

The aqueducts and cisterns of Constantinople

The system of aqueducts that supplied Byzantine Constantinople with water had more than 500 kilometers of channels. These channels fed hundreds of cisterns. The largest were open pools (one, now drained, houses an entire modern shopping center); but the most impressive were vast covered chambers like the Basilica Cistern, still a highlight of any visit to Istanbul.

Visualizing Byzantium in the year 1200

This is a computer reconstruction of the Byzantine capital at its apogee, just before the Fourth Crusade. Alongside detailed renderings of the Hippodrome and Hagia Sophia, it includes dozens of the imperial city’s less famous monuments, many of which can still be found in modern Istanbul. The reconstruction is a work in progress, and the Byzantium 1200 X account routinely posts updates.

Hagia Sophia, Istanbul's most famous and controversial landmark

A short video about the iconic Byzantine church. Still Istanbul’s most famous and, since its reconversion to a mosque, most controversial building. The recognizable dome has partially collapsed several times over the centuries, but remains a marvel of engineering. The mosaics, though fragmentary, are among the finest ever created and trace both the gradual evolution and the remarkable continuity of Byzantine art.

The unusual connection between Venice and Byzantium

This article explores the complicated relationship between Venice and the Byzantine Empire. Venice grew up in the shadow of Byzantium, serving as a trade partner and faithful ally for centuries. Gradually, relations grew hostile, and Venetian ships would carry the Fourth Crusade to its fateful rendezvous with Constantinople. Visitors to San Marco can still see marble and porphyry from Constantinople, built into the walls of Venice’s preeminent church.

What was the Fourth Crusade?

Originally destined for Jerusalem, the Crusaders became entangled in a Byzantine civil war, and found themselves besieging the greatest city in Christendom. After breaching the sea walls and subjecting the city to the worst sack in its history, they installed a Flemish nobleman as Latin emperor of Constantinople.

The rise and fall of the Byzantine Empire

A short but informative TED-Ed video summarizing the most important aspects of Byzantine civilization: how it all started, why Constantinople was so special, a few remarkable Byzantine authors (including Princess Anna Comnena, historian of her father’s reign), the Ottoman conquest, and why don’t just call the Byzantines “Romans.”

The underground cities of the Byzantine Empire

This TED-Ed video explores the mysterious cave cities of Cappadocia. Although their oldest sections may go back to the Bronze Age, most of these subterranean complexes were excavated during the Byzantine period, when the locals went underground to take shelter from Arab raiders. Monasteries were also cut into pinnacles of the local tufa, and decorated with frescoes that have often survived to the present.

Exploring the Hippodrome of Constantinople

The Hippodrome had room for about 80,000 spectators (more than the Colosseum, but less than Rome’s Circus Maximus). It was simultaneously Constantinople’s premier entertainment venue and its greatest political theater: the emperor routinely watched the games, and sometimes communicated with the crowd through a herald. The worst riot in Byzantine history, the Nika Revolt, began when the factions of the Hippodrome united in opposition to Justinian.

The western Roman Empire fell in the 5th century CE amid invasions, weakness

A mix of over-expansion, political instability, a weak military and economy, and the broad invasion of the Eurasian Huns prompted the downfall. Its eastern half, the Byzantine Empire, would last for another millennium.

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.

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 wall separating East and West Berlin was a highly visible symbol of the Cold War

Built in 1961, the Berlin Wall physically separated East and West Berlin for nearly three decades—preventing East Germans from fleeing to the West. Its fall in 1989 signaled the collapse of communist regimes across Eastern Europe.

How the Code of Justinian formed the basis of modern law

This video explores the significance of Justinian’s Corpus Juris Civilis. The most important component of the Corpus, the Digest, collected the opinions of eminent Roman jurists. The Digest went on to become the legal framework of medieval Europe, and the basis for the civil codes used across two-thirds of the globe today—an underappreciated legacy of Byzantium.

Leaning Italian tower could fall after nine centuries

Italian officials have secured the area around one of two 12th Century towers in Bologna, fearing its leaning could lead to collapse. Could it fall? Read up on the city's efforts to secure it here.

Why did the Ottoman Empire violently target Armenians during WWI?

In anticipation of threatened Allied landings at the strategically important Gallipoli peninsula, Ottoman authorities arrested 240 Armenian leaders in Constantinople on April 24, 1915, and deported them east. This roundup is commemorated today by Armenians as the beginning of the genocide, according to this article.

The White House still has its original stone walls

Construction of the White House began in 1792 and continued even after 1800, when John Adams moved in. Despite being burned by British troops in 1814 and repeatedly renovated since, the White House's original Virginia sandstone walls remain intact.

Tenochtitlan, the Aztec Venice of Mesoamerica

Tenochtitlan was the capital city of the Aztecs, founded around 1325 on an island in Lake Texcoco, in what is today Mexico. It was a major political, economic, and religious center until its destruction by the Spanish in 1521. This video explores the marvels of the city, which began as an island but grew via causeways and in-filled land and culminating in a North American Venice.

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

Lego stop motion reenacts the longest battle in World War I

One of the longest and bloodiest battles of World War I, the Battler of Verdun was a deadly conflict between French and German forces for 10 months in 1916. Some 300,000 lives were lost, but ultimately the French triumphed. This video provides a stop-motion reenactment of the battle in Lego bricks.

Da Vinci’s ingenious self-supporting bridge

Without using glue or nails, the brilliant polymath Leonardo Da Vinci was able to construct a sturdy bridge of wood logs. This video unpacks the genius civil engineering behind this concept and offers a visual demonstration of how it worked. See how Da Vinci accomplished this feat without using permanent parts, and how his bridge got even stronger as weight and force was added.

The Middle Ages produced inventions that still our lives today

Far from a “Dark Age,” the medieval era brought about significant innovations—from the printing press and mechanical clocks to navigational tools and early computing devices. This curated list of inventions demonstrates how profoundly medieval creativity has shaped the modern world.

The Dokos shipwreck, the oldest discovered to date, is more than 4,000 years old

Many of the oldest shipwrecks yet discovered sank during the late Bronze Age as Mediterranean trade networks began to flourish. This video explores the nine oldest wreckage sites, topped by the wreck off the Greek island of Dokos.

Inside the most crowded place on Earth

Once the densest place on Earth, Kowloon Walled City was a chaotic labyrinth of stacked homes, hidden corridors, and thriving underground life.

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.

How William the Conqueror expanded into England

It took William "the Bastard," the king of Normandy across the English Channel from England, over two decades so solidify control of the land he famously conquered in 1066. This video explores the audacious, risky history of the Norman king's move, focusing on the role the Bayeux Tapestry played as propaganda for the famous conqueror.

Before dynamite was invented, Erie Canal builders blasted rock with gunpowder

Constructed decades before the invention of dynamite, the Erie Canal’s toughest obstacles were blasted through using black powder charges.

What a Chinese invasion of Taiwan would look like

If China invaded Taiwan today, it would not be an easy task. This four-minute video explores the obstacles and opposition the Chinese military would face during an attack on the island. Distance, Taiwan's military spending and training, and weaponry designed to oppose an attack from the sea are all factors that would prevent an immediate win by China.

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.

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

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

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

Massive 3D printers have been used to build homes by stacking layers of 'concrete toothpaste,' a fire-resistant material that effectively insulates against outside noise.

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

Learn more about the history of fireworks, which dates back to an accidental invention during an alchemist's quest for information about immortality.

Before the current East Wing ballroom project, only two White House renovations in the past 100 years cost more than $10M.

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

Watch this video that uses Lego bricks to explain how venture capital works.

The Mona Lisa's celebrity status and repeated restorations have obscured what made the painting so revolutionary for its time

Explore the known asteroids, comets, and spacecraft involved in asteroid studies within our solar system with 'Eyes on Asteroids,' a 3D visualization from NASA.

Double world record holder Hunter Ewen helped conquer his fear of balloons, called globophobia, by training to win Guinness World Record titles for balloon inflation.

Iran's Revolutionary Guard Corps is independent of Iran's regular army and is one of the most powerful and influential military-political organizations in the Middle East.

In 1945, Surrealist artist Salvador Dalí and legendary animator Walt Disney began collaborating on a short film that was not completed until 2003, years after both men had died.

In 2019, a laptop loaded with six of the worst malware in history and described as 'an exhibit of historical weaponry' sold for $1.3M.

American short story writer Flannery O'Connor raised 40 peacocks, which became potent symbols for her fiction's elegant violence

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.

Fish populations in the Great Barrier Reef have increased after installing waterproof speakers on the ocean floor that played recordings of sounds from healthy coral reefs.

A small portion of The Winstons' 'Amen, Brother,' an obscure '60s gospel record, is the basis for thousands of hip-hop tracks, making it one of the most sampled records ever that's informally known as 'the Amen break.'

Explore what it's like inside a patient isolation unit, used in situations such as treating a patient or suspected patient with Ebola.

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

Sony set the standard for cylinder-shaped batteries when it repurposed manufacturing equipment used to make rolls of magnetic recording tape.