Who cleans the London Underground at night?

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.

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.

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.

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.

Cleaning a glass bridge 4,000 feet in the air

Dangling 4,000 feet above the Grand Canyon, these cleaners risk it all to scrub a glass bridge. With a custom-built trolley and nerves of steel, they tackle one of the scariest jobs in America.

In the late 1800s, New York City streets were covered with millions of pounds of horse manure thanks to a widespread horse-driven transportation industry.

Reflections from Ben Giles, history's greatest stain remover

Starting out as a freelance window cleaner, the British cleaning legend started taking on jobs cleaning out people's garages and shacks. He soon realized people would pay top-dollar to have their worst messes cleaned up by someone else.

The sewage of New York City

Residents of the five boroughs of New York produce 1.3 billion gallons of wastewater everyday. Seventy miles of sewer pipes, first built in the mid-1800s, feed the sewage to 14 wastewater treatment and recovery plants where the waste is treated back to viable, drinkable water. See what shouldn't go down the toilet here.

Boston opened the first subway tunnel in the US in 1897

By the end of the 19th century, nearly 400,000 people were packed into less than a square mile of downtown Boston, with 8,000 horses pulling trolleys through streets choked with noise, manure, and congestion. This prompted the city to pursue a then-controversial subway system.

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.

What it takes to guard the Tomb of the Unknown Soldier

Sentinels who guard the Tomb of the Unknown Soldier in Arlington, Virginia, must do so around the clock, year-round, no matter the weather. They're also a select few: Only 735 have been permitted to serve since 1958. This documentary explores the history of the role and the strict requirements it takes to fill it.

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.

Broadway employs tens of thousands of people in various roles

While we often just think of the actors and directors who take top billing, Broadway productions operate as distinct businesses employing numerous people in various roles: stage managers, sound designers, house managers, ushers and more.

An anthropologist spent years riding garbage trucks to understand what our trash says about us

Robin Nagle rode with New York City sanitation workers to trace the hidden life of what we throw out. Her research explores what the things we discard reveal about who we are. 1440 explores the hidden life of trash.

Tokyo's transparent toilets use smart, automatic glass to make cleanliness visible

Dubbed the Tokyo Toilet project, this initiative installs restrooms whose walls are transparent when empty, so users can see whether they are clean and safe. When they lock, they turn opaque for privacy. Beyond addressing two key anxieties (hygiene and security), the project lends a distinct architectural prestige to typically banal (and reviled) toilets.

Disney World's Magic Kingdom includes utilidors—an underground system of tunnels and passageways—to hide the park's maintenance operations.

Visualizing New York City's public transportation commutes

New York City is one of the largest cities in the world, and transports one of the largest numbers of commuters on a daily basis. This data visualization tells the stories of those commuters, showing the varying volume of travelers throughout the week and day, where they are going, and maps of high-traffic areas like stadiums and midtown. Dive into the data here.

Take a tour of Charles Dickens' London

Much of Dickens' fiction concerns Victorian London and its people. This tour of the city, led by Dickens biographer Simon Callow, walks you through significant sites, like the place where Dickens' parents were married, the shoe-blacking factory where he worked as a boy, and the place where he created his first magazine.

How Monet’s paintings changed the way we see London

Between 1899 and 1901, legendary French Impressionist painter Claude Monet produced over 100 paintings of London consistently shrouded in fog. Art historians claim this series left a permanent mark on how we perceive the capital city, inevitably layered in obscuring and dramatic mist. See some of the paintings and read more 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.

More than 500,000 people worked to contain Chernobyl's fallout, many with very little radiation protection.

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.

In 1971, a $35 ferret helped clean the Fermi National Accelerator Laboratory

Lacking cleaning robots, Fermilab scientists purchased a ferret named Felicia when metal slivers obstructing accelerated particles were identified. They trained her to run strings through vacuum tubes more than 90 meters long, and cleanser-dipped swabs were then tied to the strings and pulled through to remove the debris.

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.

Fire engines are among the most complex vehicles on the road

These vehicles are purpose-built to carry water, foam, hoses, ladders, and lifesaving equipment to a scene in minutes. This animated video pulls apart every system inside a pumper truck, showing exactly how the machinery that fights fires actually works.

Manholes connect underground sewer and water drain pipes

Wherever a portion of sewer is connected to another, a manhole is built. These serve both as access points for maintenance and as connectors for the system. This video shows how crucial manholes are for proper sewer functioning.

The Federal Transit Administration distributes roughly $20B annually to support local transportation

Created by the Urban Mass Transportation Act in 1964, the FTA funds and oversees the roughly 2,200 transit systems that receive federal support across the US, covering everything from subway capital investment to rural bus service.

Explore stories from riders of San Francisco's transit system

Since 2008, the "Muni Diaries" podcast has collected true stories from more than 4,000 transit riders, from a man riding with a black crow on his shoulder to the bus driver who moonlights as a poet.

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.

In the '70s, graffiti moved to subway cars

Unlike static walls, the silver cars moved throughout the city, like a canvas in perpetual motion. That made them highly desired by graffiti artists, especially because tagging them was considerably more difficult and, in turn, more impressive than a simple tag in an alley.

With roots stretching back to the 18th century, unions have long been at the center of change in labor rights.

The 'chief usher' manages the White House and a staff of roughly 100 people

Tracing back to 19th-century household roles, the chief usher is now the White House's general manager—overseeing renovations, maintenance, food service, budgets, and employees who run the daily operations of the complex.

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 forgotten carnivals that stood upon the frozen River Thames

The Thames Frost Fairs were unusual winter events that took place between 1607 and 1814. They happened during the so-called Little Ice Age, when the River Thames would freeze over for up to two months straight. These unique festivals transformed the frozen river into a bustling carnival-like environment where Londoners set up temporary shops, entertainment venues, and social spaces directly on the ice.

Thousands of quarters and huge water bills: the economics of laundromats

There are approximately 30,000 laundromats in the US, serving the roughly 50% of apartment dwellers who do not have a washer or dryer. Shops profit when they can get their machines—roughly 30 to 40 per location, on average—to wash eight to 10 loads a day. Connections with commercial vendors help.

John Snow—not the one from 'Game of Thrones'—determined that contaminated water sickened London

His pioneering epidemiology work during an 1854 cholera outbreak mapped out the commonalities between people in London who were getting sick. He discovered that ill people were getting water from the same Broad Street pump. Before Snow's work, the prevailing theory was that bad air sickened individuals instead of cholera-causing bacteria in the water.

A day in the life of a leafcutter ant

Among the fascinating world of insects, leafcutter ants form some of the most complex and dynamic social ecosystems. All part of an effort to keep a colony alive, worker ants toil tirelessly, dragging bits of leaves and vegetation back to their...

Explore the 2025 Uber Lost & Found Index to find out the weirdest items that passengers left behind in Ubers last year, from ten live lobsters to a mannequin head with human hair.

On a cruise ship, the average person uses about 50 gallons of water a day, which is treated by bacteria and onboard filtration systems, then stored until the ship can legally discharge the wastewater.

A day in the life of a bedbug exterminator

Hugh Barrie is a bedbug specialist known as the Bed Bug Doctor, in Sussex, United Kingdom. Barrie employs a unique approach to bedbug extermination using heat treatment. Follow along as one journalist goes through the daily motions of a bedbug...

Newspaper delivery people, trash collectors, and more: who to tip and how much

The suggested holiday tip amount for garage attendants is between $10 and $50, whereas the suggested holiday tip amount for doormen in apartment buildings is between $25 and $100 each.

How often should you clean your water bottle?

Experts say a daily wash of a high-use bottle is key to keep away unwanted bacteria and odors. For a good clean, use water—as hot as 140 degrees Fahrenheit—mixed with soap, swirling the mixture in the bottle before letting it sit for 20 minutes. Learn more tips with this quick overview.

What do archaeologists actually do?

Movies and other media show them digging a bit, maybe fighting off artifact smugglers, but what archaeologists actually do? Using a variety of tools and sciences, archaeologists are able to get a glimpse into humanity's past. This article explains what work is like for everyday archaeologists.

Transit is funded through a three-tier system, and the federal government is the smallest piece

In 2019, the federal government covered about one-sixth of the $79B spent on public transit. States and localities make up the rest. About 85% of all transit trips are taken by bus or heavy rail, and nearly 4 in 10 US transit trips occur in the New York City metro area.

Modern landfills use layered liners, leachate systems, and gas monitors to safely contain waste

Today, landfill engineering is far more complex than a hole in the ground, which was largely the system cities used less than a century ago. This video explains how it actually works.

The Foolkiller: the mysterious submarine at the bottom of the Chicago River.

In November 1915, a submarine was found at the bottom of the Chicago River. It had been there for at least 10 years, was 40 feet long, and contained the remains of a man and his dog. To this day, no one knows who built it.

Local governments are responsible for more than 148,000 public water systems across the US

From large municipal utilities to small rural systems, local governments are tasked with providing clean water to almost every American community. The US operates over 148,000 public water systems.

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.

Listen to a jazz composition triggered by the New York City Subway

A creative coder created a (synthetic) jazz ensemble that uses the locations of the city's trains to determine its performance. It's both a fascinating bit of internet culture and a fitting homage to New York, one of jazz's major hubs.

The marvels of mucus

Mucus—otherwise known as snot or phlegm—has a gross reputation, but the substance is actually of vital importance, lining the moist surfaces of our nose, intestines, lungs, and more. It plays a constant role in keeping our tissues from drying out and acts as a line of defense, but if it gets too sticky or thick, it can cause problems. Read about the marvels of mucus here.