While constructing the tunnel connecting the UK and France, satellite positioning systems were supplemented by paleontologists on either side of the tunnel, who analyzed fossils to ensure excavation was at the correct depth.

The wild, early history of the tunnel across the English Channel

Britain and France today are connected by the Chunnel—a tunnel bored roughly 120 feet under the seabed of the notoriously choppy English Channel, which opened in 1994. The dream of integrating Britain with the rest of the continent this way began much earlier, with daring, physically impossible plans proposed as early as the 19th century. Check out the earliest plans here.

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.

The archaeological sites uncovered through London's Crossrail Project

The Crossrail Project is an underground train system in London, which saw 26 miles of new tunnels created over more than a decade. The project provided unique access to long-buried layers of London's history, and a massive parallel archaeological excavation took place.

The Large Hadron Collider repurposed an excavation tunnel built for the Large Electron-Positron Collider, which was used until 2000 and whose construction involved the largest civil engineering project in Europe before the Channel Tunnel.

Watch animations of the creation and excavation of dinosaur tracks

The discovery of a dinosaur trackway in the UK emerged from a controlled explosion that removed limestone from an Oxfordshire quarry. The footprints provide unique insights into dinosaur behavior and movement, with marine fossils suggesting a lagoon-like environment.

As of 2025, humans have only dug 0.2% the way to Earth's center

The Kola Superdeep Borehole revealed two billion-year-old fossils and underground water, but the immense temperature and pressure prevented further tunneling. Beyond those depths, scientists know of Earth's interior by analyzing how seismic waves move.

The booming fossil industry on the Jurassic Coast

Ever since the Jurassic Coast was registered as a UNESCO World Heritage site in 2001, professional and amateur fossil-finders have increasingly set out for its craggly cliffs to discover ammonites, icthyosaurs, and even new discoveries. This photo essay takes a human look at the growing interest and industry in fossil discoveries along the famed 95-mile strip of England.

Detailing the horrific conditions of life in the trenches

What was it like to live and fight in a trench during World War I? If you were on the German side you might have bunkers, electricity, and other basic comforts. If you were on the British and French side the conditions have been described as muddy and "horrific". Find out how unpleasant trench warfare was and how it affected WWI soldiers.

Located in the Pacific Ocean, the Challenger Deep is the deepest point on Earth, extending to depths a mile deeper than Mount Everest is tall.

New scientific tools, such as radiocarbon dating and DNA analysis, have transformed what we know about who built Stonehenge.

Techniques such as radiocarbon dating, DNA analysis, and isotopic testing have revised scholars' understanding of Stonehenge. This article presents evidence suggesting that societies were more cooperative and less violent than earlier theories had suggested.

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.

Stonehenge was built using giant wooden rollers and precisely carved tongue-and-groove joints to lock the stones in place.

This short animation shows how human beings managed to lug 30-ton stones over miles of prehistoric English countryside and stand them up The Stone Age engineering involved using giant wooden rollers and carving precisely interlocking tongue-and-groove joints to hold the heavy stones in place.

The US finished what the French had started with Panama's canal

For about two decades, Suez Canal-builder and Frenchman Ferdinand de Lesseps led the project, but financial troubles forced it into the hands of the US, who completed it in 1914. This timeline, made to accompany the definitive PBS American Experience documentary about the canal, highlights major moments in its construction.

NYC's first subway was built largely in secret

In 1870, Alfred Ely Beach secretly tunneled under Broadway in 58 nights, disguising his pneumatic subway as a mail tube to fool Tammany Hall, the corrupt political machine that ran New York City. Nearly half a million New Yorkers rode it before politics, and a stock market crash killed the project.

The deepest human-made hole on Earth is in Russia’s Arctic North

Driven by Cold War competition, the Kola Superdeep borehole was a project in the 1970s to uncover the composition of the Earth by boring underground. The mission managed to go 7.6 miles into Earth’s crust, the deepest human-made hole on Earth.

Scientists discover what looks like an underwater road

Crew aboard the Exploration Vessel Nautilus discvered a “yellow brick road” that looks it leads to Atlantis. Climage change may affect future ocean studies.

Although an estimated 99.999% of the deep ocean has not been explored, techniques such as sonar have been used to identify the deepest known point in each of Earth's five oceans.

Roughly 25,000 workers died building the canal

For each mile of canal that was built, 500 workers lost their lives. The threats came from multiple fronts: mudslides, floods, earthquakes and disease-carrying mosquitoes. Workplace accidents became so common that artificial limb manufacturers competed for contracts with the canal builders.

How paleos dig up dinosaurs

Follow Kelsie Abrams and the dig team from the field to the lab, as they unravel mysteries from the end of the age of dinosaurs.

Deep-sea trenches form when one tectonic plate subducts another underwater

Oceanic plates sink when colliding with less dense continental plates, bending the seafloor into steep depressions that can be almost 11 kilometers deep. Many of Earth’s strongest earthquakes occur at these plate boundaries, often featuring volcanic activity.

A fun, illustrated history of the Jurassic Coast

The 95-mile stretch of coastline along England's southern shores known as the Jurassic Coast is unique in the world due to its clear demonstration of 185 million years of geological history. Now, you can see the story of that formation told in a whimsical, absorbing video created by artist Tim Britton and his pen.

The ancient Egyptians built prototypes of the modern Suez Canal

The idea to facilitate trade between the Mediterranean Sea and the Red Sea and connect the Eurasian continent was apparent even to pharaohs in the second millennium BCE. Though no physical traces remain, contemporary accounts attest to early, shorter versions of the canal, including from Herodotus.

A case study of how engineers and geologists at Tullow Oil look for oil reserves

An analysis of surface rocks using aerial and satellite imagery can help narrow the search for crude oil by identifying basins where sedimentary layers have compacted—a key process in oil formation. Surveys that look for variations in Earth's gravitational and magnetic fields consistent with specific rock distributions, or that use sound waves reflected off rock layers—not unlike sonar underwater—can also help map subsurface geology.

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.

Learn about the construction of the undersea fiber optic cables carrying internet data

Over 750,000 miles of fiber-optic cables run along the seafloor, serving as a freeway for the Internet's data. Despite subsea cable projects costing hundreds of millions of dollars, depending on the length of the cable, it remains the fastest and most cost-effective way to send information.

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.

Thunderquakes—seismic waves created when lightning strikes the ground—have enabled scientists to image underground environments near Earth's surface by detecting vibrations along subterranean fiber-optic cables.

Fossils form in environments where dead organisms can be rapidly buried

Such landscapes enable corpses to be encased by terrain before significant decay occurs. They are most commonly found in river deltas and sinking coastal regions, where sediments accumulate over time until geological forces expose the areas to erosion, revealing embedded fossils.

Paleontologists apply rules about rock layering, fossilization, and radioactivity to date geological samples

Concepts such as the understanding that older rock layers will form beneath newer ones allow scientists to compare the ages of samples from various layers. Although no geological site preserves evidence across all time, samples can be combined with fossils of known age, such as those dated by analyzing the decay of their radioactive isotopes, to reconstruct Earth's timeline.

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.

Working conditions on the Panama Canal, built between 1904 and 1914, were abysmal, with thousands of workers dying on the job.

How do archaeologists know where to dig?

Archaeologists spend their days slowly uncovering buried artifacts, but how do they know where to look in the first place? New tech and old-fashioned shoe leather. Watch this five-minute video to learn more.

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.

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.

Scale models show the intricacy of WWI trench warfare

Every inch of these models of WWI soldiers in the trenches is crafted with amazing details, right down to the real-life letters written to home.

Take a virtual tour inside Stonehenge, the stone monument built roughly 5,000 years ago.

Prehistoric visitors approached Stonehenge along a processional route known as the Avenue, where the sunrise of the summer solstice aligns with the sarsen stones. This interactive 3D tour recreates that experience with explainer videos and detailed sidebars.

How deep is the Mariana Trench?

This five-minute video takes viewers to the depths of the Mariana Trench, emphasizing just how far below the bottom of the trench lies beneath our feet through comparisons to better-known objects and monuments, including the Eiffel Tower. The Statue...

Quantum tunneling allows particles to pass through classically impenetrable barriers

First described in 1928, the phenomenon is the result of probability waves, which represent the location of particles in space as extended objects. Just as sound waves can reflect off of and pass through barriers, these probability waves dictate that solid matter has a chance at passing through obstacles.

In 2022, a piece of Challenger was discovered on the ocean floor

While searching for World War II wreckage near Cape Canaveral, Florida, for a documentary, divers discovered debris on the seafloor that NASA later confirmed to be a piece of Space Shuttle Challenger wreckage. The piece is at least 15-by-15 feet in size and partially buried under sand.

The massive sinkholes of China

Parts of China's limestone-rich terrain is fertile ground for massive caves, where some of the world's largest sinkholes are located. Hidden away in dense, lush forests, geologists are frequently discovering new sinkholes to explore. This piece...

Soar above the Jurassic Coast’s 185 million years of geology

This sweeping drone video reveals the stark beauty of the UK’s Jurassic Coast, a 95-mile stretch where Triassic red rock, Jurassic layers, and Cretaceous limestone are exposed—one of the clearest visible records of the Mesozoic era on Earth.

Explore a searchable map of underwater cables carrying internet traffic worldwide

The Submarine Cable Map provides users with data from TeleGeography's Transport Networks Research Service on individual submarine cables, including cable owners, suppliers, URLs, landing points, lengths, and notes of interest.

Stonehenge is one of the world's most studied prehistoric sites and was built around the same time as the Great Pyramid of Egypt.

Watch a time-lapse of the installation of the New Safe Confinement structure

The world's largest movable metal structure was built to contain the radioactive material from the 1986 Chernobyl disaster, which had previously been confined within a structure built to last no more than 30 years. The new structure was slowly rolled along rails over the course of two weeks.

Watch a visualization of the construction of Chernobyl's sarcophagus

Built to contain the remains of Reactor 4 after the nuclear disaster, the "shelter structure" was constructed from about 400,000 cubic meters of concrete—enough to fill 160 Olympic-sized swimming pools. Construction required vehicles and cranes modified with special shielding to protect workers.

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.

What revisiting a 1979 experiment reveals about ecosystem recovery after deep-sea mining

A 2023 study co-led by the National Oceanography Centre and the Natural History Museum, London, found that tracks made by the mining vehicle remained largely unchanged since 1979. Small animals, such as amoeba-like xenophyophore, were seen in the cleared areas, but sightings of larger animals known to live in the region were much rarer. (Some readers may experience a paywall.)

In 2025, UK scientists began studying climate data from a 1.5-million-year-old ice core

The Antarctica sample will be melted and analyzed in Cambridge to learn about prehistoric environmental conditions. Researchers hope the ice core reveals how Earth's glacial cycles shifted dramatically around 800,000 years ago.

American oceanographic cartographer Marie Tharp's discovery of the Mid-Atlantic Ridge, which supported the idea that continents move over time, was initially dismissed as 'girl talk.'

Local limestone made waterproof cement for the Erie Canal

In 1818, engineer Canvass White discovered that limestone near Chittenango, New York, could be processed into hydraulic (or waterproof) cement. This breakthrough replaced costly European imports, enabling watertight locks and aqueducts and revolutionizing American construction.