How the underground maze below the Gaza Strip works

The simplicity of immersed tube tunnels

Tunnels have traditionally bored holes through the earth below the water. On the other hand, immersed tube tunnels connect hollow, massive sections in trenches along the floor of the body of water. Each section is built on land, floated to the site, submerged, and connected. This method saves money by reducing expensive underground work, and it preserves an area's aesthetic appearance.

Essential pipes, sewers, and cables lie buried beneath New York City

The Department of Design and Construction offers a tour of its work sites, explaining the complex systems that exist underground. Gas, electrical, telecom pipes, and many others, sprawl out underneath the entire city, with dozens of maps that help workers know where they're placed. This layout is unusual compared to the rest of the country, where wires are often present and visible above ground.

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 West Berlin student dug a tunnel under the Berlin Wall—29 East Germans escaped

This podcast recounts how a young West Berlin student excavated a secret 135‑meter tunnel beneath the Berlin Wall in 1962. A total of 29 East Germans escaped to freedom, even as a Stasi mole threatened exposure.

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

Toronto's downtown has 18 miles of underground pedestrian tunnels

Known as the "Path," these tunnels have helped reduce pedestrian traffic on Toronto's busy downtown streets for over a century. They were first built by local business owners, prompting a network effect of add-on tunnels.

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.

One graffiti artist turned a train tunnel into his gallery

Chris Pape, also known as Freedom, began exploring a tunnel under Manhattan's Riverside Park when he was a kid. As he grew more involved with graffiti, he turned its walls into a massive art project, one that reflected both the history of graffiti and the people who made the tunnel their home.

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.

What can be found underneath the Saharan sands?

Watch this 19-minute video to learn more about what can be found under the Sahara Desert, which spans almost all of northern Africa and is one of the largest deserts in the world. Deep under the Sahara desert sands lies evidence of life that once...

How flooding the Dead Sea could help the climate

There are many dead zones in the world with low elevation and very little rainfall that provide little to no benefits to the ecosystem or climate. This digestible, thorough article explains how piping in nearby water to flood these areas could...

The story of Palestine through the eyes of its people

Issues of identity are crucial to understanding Israel-Palestine. This site weaves individual narratives with key historical moments and common Q&As around the Israeli-Palestinian conflict. Ordinary people share personal stories about surviving massacres, displacement, and military occupation. And young Palestinians from across the world reflect on their identity, life under occupation, exile, and future aspirations. Explore what it means to be Palestinian through this interactive site by Al Jazeera.

The three theories explaining how the pyramids were built

There's no consensus over how the ancient monuments were built, and no blueprints left behind. But centuries of study have produced three competing theories: a simple, massive external ramp, a more complex internal ramp, or a highly sophisticated water elevator.

There is a secretive bomb-proof bunker located under the White House

Built in 1942 during World War II, the Presidential Emergency Operations Center lies beneath the East Wing. Designed to protect the president during air raids—and later nuclear threats—it remains a top-secret command site used during crises like 9/11.

Go inside a real beehive with this interactive

Beehives are where the magic honey-making happens, where thousands of honeybees beat their wings, throw up partially-digested nectar to further purify it into sugars, and make wax. The goings-on of a beehive—the name for a man-made habitat for...

Watch an ethical hacker provide a tour of the dark web

Cybersecurity researcher John Hammond explores the effectiveness of a dark web search engine, leaks from ransomware group data breaches, and a categorized index of dark web links, including some that are alleged to host malware. Many dark web sites are no longer active or host scams to fool unsuspecting visitors.

A basement of mechanical systems—collectively called the technosphere—supports B2

Twenty-six underground air handlers heat, cool, filter and manage the humidity of the air across the biomes of Biosphere 2. The above-ground Energy Center complex provides continuous power to these and other systems, including heating and cooling water for laboratory experiments and personal use.

Landfills capture methane gas and convert it into usable energy

As organic waste breaks down underground, it produces landfill gas that is roughly 50% methane. That gas can be captured and used to generate electricity or provide heat for nearby homes and businesses.

The complex production machine behind Eurovision

This short Wall Street Journal documentary goes behind the scenes at Eurovision to show how the elaborate stage show—which features a production manager, speedy run crews, and a digital floor outlining the location of every prop for every performance—hums along so smoothly.

Watch a drone flight through a fireworks display

This video explores the history, construction, and preparation of modern fireworks displays, including creating gunpowder from scratch. Experimentation with fireworks underwater is also featured, but they require special materials to prevent water from infiltrating the fireworks shell.

Behind the fascinating disguising mechanism of camouflage

Camouflage—nature's master game of hide-and-seek—is more complex than simply how things look. The disguising process required millions of years of evolution that have programmed how our brains take shortcuts. Watch this video to see examples of camouflage and understand how we process it.

There's a bitcoin mine in remote Zambia

In Zambia, a small hydropower plant draws water to power a town of 15,000 people—and a bitcoin mine. A shipping container containing 120 computers mining bitcoin—solving complex calculations to win the reward of several bitcoin—was set up near the plant to use its cheap electricity, and share its revenue.

The myths around London's tiniest sculpture

The Philpot Lane mice have been considered London's smallest sculpture for decades, delighting visitors and locals alike. But there's a common story told for why the unusual sculpture—which features two mice fighting for a piece of cheese—was placed there, saying it commemorated the death of a construction worker fighting over a lunch in the 1800s. The author of this article argues the evidence for such a story is lacking. Dive into the obscure history here.

Video and still images are combined with sonar data to create seafloor maps

Sonar works by sending thousands of sound pulses per second towards the seafloor, capturing the strength and timing of the returning echo. This data can accurately reveal depth, seafloor texture, and the presence of fish habitats to millimeter resolutions.

The trajectory of particles in bubble chambers reveals their properties

The presence of magnetic fields produces spiraling paths in charged particles as they move across the field, with faster and more massive particles moving in wider turns. Gaps in the trails indicate the presence of short-lived particles that are undetectable until they decay.

View a gallery of diagrams for each volcano type with glossaries

The three major types of volcanoes—cinder cone, composite, and shield—each exhibit unique, lesser-known subterranean and surface features, including lava bombs, lahars, and spatter. Other types of volcanoes include lava domes, calderas, fissure volcanoes, and Maars and tuff rings.

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.

Watch how deep-sea mining equipment collects and processes polymetallic nodules—metal-rich, potato-shaped rocks—from the ocean floor and creates environmentally damaging plumes of sediments.

A 2019 Facebook event called on attendees to "Storm Area 51, They Can't Stop All of Us," resulting in countless memes, the creation of a music festival, and eventually the arrests of those who did try to approach the area.

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

See these 16 pieces of art evoking phobias of snakes, flying, spiders, and more. 

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.

Most of the observable universe's volume consists of voids and supervoids—enormous regions of space with little to no galaxies, stars, or light.

Discover the catastrophic consequences of a failure of the US electrical grid—something that is more likely than many Americans think.

When you complete a CAPTCHA on a website to prove you are human, you may be unknowingly training algorithms for self-driving cars, whose systems require training data to help identify crosswalks, bicycles, and other outdoor objects.

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

Gerrymandering works through two techniques: cracking opposing voters across districts to dilute their power, and packing them into a few to waste their votes in lopsided majorities.

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, 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.

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.

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

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

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

Hedge funds, the private investment firms that trade a wide swath of financial assets, make money by imposing steep fees on investors and from the fund's investment performance.

Netflix profits when you're not watching, and its movies are designed that way—read a detail-rich critical essay exposing lesser-known Netflix takes

US intelligence allegedly pursued more than 600 schemes to assassinate Cuban revolutionary Fidel Castro.

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.

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.

Researchers believe the brain consolidates memories, processes emotions, and plans for the future during dream states

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.