The underground cities of the Byzantine Empire

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

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 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.

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.

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 mosaics of San Vitale, Italy's Byzantine city

This video explores the unique artistic heritage of Ravenna, the center of Byzantine power in Italy. The city’s churches and baptistries still sparkle with a dazzling array of Byzantine mosaics. The most famous of these, in the Church of San Vitale, show Justinian and his wife Theodora with their courtiers. A visit to Ravenna – or at least a look at this video – is highly recommended to anyone interested in Byzantine history or art.

A map of the Byzantine Empire

This map, hosted on the World History Encyclopedia, shows the Byzantine Empire in four eras. The area shaded dark purple is the original Eastern Roman Empire. The light purple areas represent the conquests of Justinian. The dark purple line surrounds the middle Byzantine Empire. The hatched area, finally, indicates the small “Latin Empire” established after the Fourth Crusade.

Enter the Mayan underworld through this 3-mile cave

Discoveries in Belize's Actun Tunichil Muknal (ATM) cave suggest the cave was once a significant site for sacred Mayan ceremonies in antiquity. New research reveals how the Mayans conducted rituals to re-enact a specific creation myth, often staged in desperate times and aimed to invoke the gods for a "rebirth" amid drought and turmoil. Read more on the enigmatic research here.

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.

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.

A look at some of the world's most unique churches

From a skeleton-adorned church in the Czech Republic to wooden churches built without nails in Russia, this video explores some of Christianity's most intriguing architectural feats. These places of worship were built in remote areas throughout history, and show amazing innovation. See a fascinating glimpse into the overlooked structures, along with stories of how and why they came to be.

Why did this prehistoric culture regularly burn their homes?

This article explores why the Cucuteni-Trypillia culture may have regularly burned their homes. The Cucuteni-Trypillia culture is the oldest known in Europe, dating back to about 5,500 BCE in present-day Romania, Russia, and Ukraine. The...

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

What techniques did cave painters use to create their work?

Cave paintings long predate local craft stores and premade paints, so what techniques and tools did cave artists use to create such long-lasting works? This video gallery details how ancient artists inscribed and painted their work on cave walls, specifically the Chauvet cave in France.

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.

The land where Greece's ancient language survives

In a remote corner of Turkey, locals speak Romeyka, a language with no written form and an "impressive" similarity to ancient Greek. This article details how the language may have survived and highlights the roughly 5,000 Romeyka speakers in the area. Research shows that Romeyka bears a startling resemblance to the Koine Greek spoken at the height of ancient Greek influence between fourth century BCE and fourth century CE.

Speleothems are diverse mineral formations that form in air-filled caves

Speleothems like stalactites and stalagmites form when water deposits minerals after a cave rises above the water table and fills with air. These formations preserve the mineral deposits, which may serve as climate proxies, for as long as a million years.

How the underground maze below the Gaza Strip works

Hamas militants have constructed a web underneath the Gaza Strip filled with tunnels, residential areas, bunkers, and more. This article and illustrations explore the underground maze as detailed in photo and video evidence and witness accounts.

Pompeii Explained

Buried under 20 feet of ash in 79 CE, Pompeii preserved villas, street-food shops, frescoes, and victims’ casts in extraordinary detail. Excavated from 1748, it offers a rare glimpse into Roman life, still overshadowed by the active Mount Vesuvius.

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

The 15 most beautiful caves in the United States

The United States is home to more than 45,000 caves, including many with National Parks designation, like Wind Cave (in South Dakota) and Carlsbad Caverns (in New Mexico). This list of the 15 best isn't just for spelunkers—all of these sites are available for more typical tourists, so long as they have a good pair of shoes.

The ancient origins of focaccia

Focaccia, the Italian flat oven-baked bread that’s often a canvas for delightful culinary artwork, has been around for thousands of years. Archeologists have recently discovered evidence of flatbreads similar to today’s focaccia dating back to the Late Neolithic period in the Fertile Crescent. Researchers believe that communities from present-day Syria and Turkey made these distinctive loaves for large gatherings. Learn more about the bread’s history in this Archeology News article.

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.

Six myths about the Middle Ages

The Middle Ages, or medieval era, refers to roughly 500 CE to 1,500 CE. Contemporary opinion perceives this era as "dark" or backward because it was the time between the fall of Rome and the rise of the Renaissance. But much of the era was vibrant, and many myths are just that, including the idea that most people believed the Earth was flat. Watch this video to debunk more myths.

Medieval monasteries preserved ancient knowledge through hand-copied books

Medieval monks and nuns lived in religious communities devoted to work and prayer. Still, their script-copying traditions had a lasting impact: through illuminated manuscripts, monasteries preserved hundreds of ancient texts that might have otherwise been lost.

Why are subway walls tiled?

In the early days of subway tunnels, architects needed to deal with dirt and moisture and make the cavernous stations less dank and dark. Ceramic tiles were easy to clean, and their glossy, bright finish helped illuminate the cave-like areas.

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

Explore the deepest parts of the ocean

The deeps of the Earth's oceans are some of the most extreme environments on the planet. Take a trip 36,000 feet to the deepest parts of the sea in this informative, 10-minute animated video.

A look at historical ciphers, from the Spartan 'scytale' to the Navajo Code Talkers

From the Greek word for "hidden writing," cryptography in Ancient Greece took the form of batons around which a long strip of leather or parchment was wrapped, after which messages were written. Recipients needed a scytale of the correct width to encircle received ribbons and reveal the message. Members of the Navajo Nation created a code that remained unbroken throughout its use in World War II.

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

Explore the animals that populate the depths of the ocean, from fish and coral in the first few hundred feet, all the way down to the bottom of the Mariana Trench.

Scientists can determine Earth's past climate conditions by analyzing air trapped in microscopic bubbles within ice cores—columns of compressed snow layers that build up over hundreds of thousands of years.

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

Artificial coral reefs have been 3D printed from nontoxic, biodegradable terracotta clay, which coral polyps have used as a foundation for rebuilding marine ecosystems.

Children are now three times more likely to say they want to be a YouTuber when they grow up than an astronaut, with some even attending 'YouTube camps' that teach kids how to create content for the platform.

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.

Lesser-known phobias include turophobia, or the fear of cheese, and nomophobia, the fear of being without your cell phone.

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

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

According to the physics of black holes, our 4D reality may be a hologram—a projection of information coded on a 2D surface on the edge of the universe.

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.

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

The name 'Silicon Valley' arose from the founding of Shockley Semiconductor Laboratory in Fairchild Semiconductor in 1956-57, founded near Stanford University in Palo Alto

SpongeBob exemplifies Aristotle's philosophy for living well because he understands that happiness doesn't come from external factors like money, recognition, or power.

Ebola species have historically been named after where they were discovered, stigmatizing residents who live there, including Bundibugyo, in Uganda.

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.

See how Budweiser's famous Clydesdales spend their days at Warm Springs Ranch, where roughly 70 to 80 of the beer brand's giant horses can be found at any given time.

In preparation for this weekend's Eurovision finale, which is something like the World Cup of pop music, here's a young Céline Dion performing (for Switzerland?) at the 1988 competition.