Toronto's downtown has 18 miles of underground pedestrian tunnels

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.

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.

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

NYC congestion pricing a year in: traffic is down, transit is up

Manhattan's congestion pricing program has quietly become a success story. WNYC reporter Stephen Nessen examines why the original backlash to the concept has faded, how New Yorkers adjusted, and what the city's experience shares with similar policies in Stockholm and London.

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 Channel Tunnel consists of an underwater network of over 200 kilometers in length

The passage beneath the English Channel between England and France includes three tunnels, crossover chambers, emergency passages, and air ducts. Burrowing teams in either country consistently checked their coordinates to ensure they would meet within two centimeters of each other.

The 15-minute city lets residents meet their daily needs within 15 minutes on foot

Many cities have been designed with inefficient layouts that waste time and lower the quality of life of those who live there. In the 15-minute city, essential services—including work, food, education, and health—should all be located within a short walk or bike ride from where people live.

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.

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.

Abandoned malls prompt 'liminal' vibes of being stuck in time

A Toronto-area tour of empty malls brings participants face-to-face with the past. Part nostalgia, part archaeology, this meditation on the "liminal" spaces of a bygone era provokes eerie reflections on our relationship to time and place.

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.

Connected technology improves infrastructure efficiency in smart cities

Through information and communication technologies, smart cities can provide enhanced public services and improved quality of life by managing traffic and dynamic safety policies. They can also promote sustainability by automating energy use and redirecting resources according to need.

Self-driving cars may upend transit before cities can build it

Austin approved a $7.1B light-rail in 2020, but components of the plan have already been cut. Simultaneously, Waymo launched a 200-car autonomous fleet across the city. Cities now face a choice: invest in decadeslong fixed infrastructure projects or embrace flexible, on-demand autonomous vehicles that can navigate anywhere.

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.

Niagara Falls was a key Underground Railroad crossing point

In the mid-1800s, the Suspension Bridge near Niagara Falls connected the US to Canada and served as a frequent crossing location for people escaping slavery via the Underground Railroad.

The Boring Company was created by Elon Musk in 2017

While it started out as a subsidiary of SpaceX, the Boring Company became an independent entity in 2018. Musk started it with the aim of helping reduce city traffic via underground tunnels.

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.

A 2020 study suggests just 6.7% of Tor network users visit sites on the dark web

It did not distinguish between visits to malicious sites and traffic to legitimate institutions with .onion domains, such as the BBC or Buzzfeed, and thus claimed that 6.7% of anonymized users engage in nefarious activity. The low percentage still highlights that most users of the technology underlying the dark web do not use it to browse the hidden portion of the internet.

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.

The origin of shortest-path algorithms and how they became optimized for navigation apps

In 1956, Dutch programmer Edsger Dijkstra spent about 20 minutes developing an algorithm to demonstrate how computers could quickly determine the shortest route between Rotterdam and Groningen. Since then, modified versions of Dijkstra's formulation comprise the processing backbone of systems such as Google Maps and Apple Maps.

Why Amsterdam looks so unique

The Netherlands' capital consists of concentric canals lined with towering, unusually thin row homes, an altogether unique profile in Europe and the world. When it was growing, the city was a key trade hub, and merchants wanted direct access to waterways. Canals were built like roads, and houses were required to be very thin to allow for more homes to line the canals.

Microforests in urban environments may help combat climate change

Areas of densely packed native trees and drought-tolerant plants within cities can pull carbon dioxide from the air, cool surrounding neighborhoods, and support local wildlife. The idea behind microforests traces back over 50 years to Japanese ecologist Dr. Akira Miyawaki, who promoted planting whole ecosystems to restore degraded land.

Tokyo is the world's largest city by population

Home to over 41 million people, the megacity used to be a humble fishing village called Edo. Since Japan opened to foreign trade in the mid-1800s, Tokyo has made significant economic advances and achieved numerous milestones in public transportation, urban planning and culture.

Broadway is a theater district in New York

There are 41 official Broadway theaters in New York City, all within a few blocks of Times Square, a key contributor to the area's prestige and economic success. These theaters host the productions eligible for Tony Awards.

Avenues are typically wider than streets

Generally speaking, avenues are roads with buildings or trees on both sides. This article further details the differences between lanes, streets, circles, drives and more.

Drought conditions force fewer ships to sail the Panama Canal daily

In 2023, canal authorities reduced traffic in the canal amid severely dry conditions. These seven infographics from the Woodwell Climate Research Center explain exactly what happened that historically dry October, and how it affected global supply chains.

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

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.

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

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.

In 1915, workers recovered a submarine-like vessel from the Chicago River, prompting fears of German espionage

Domino's Pizza's 30-minute delivery guarantee was responsible for the chain's 1980s surge, but it was discontinued after the company was found liable for delivery driver accidents.

While the first exchange-traded fund (a 'basket' of different assets that can be bought and sold on a stock exchange) in the US only launched in 1993, the global ETF market has grown to more than $10T in the short time since.

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

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

Power lines are dotted with large, brightly colored balls to improve the visibility of these thin wires to helicopters and small planes and help prevent potential crashes.

In its famous catalog, Sears sold $600 DIY house kits from 1908 through the 1940s, resulting in an estimated 100,000 'Sears and Roebuck homes.'

Objects can be 3D printed with light by projecting 2D computerized tomography (CT) scans onto rotating cylinders of resin, which solidify upon exposure.

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 more than 1.5 million Muslims each year.

About 2,000 US babies are born annually without some portion of their limbs, potentially leading to a lifetime of pricey prosthetics.

'Silent' fireworks have gained more interest in recent years as a quieter celebratory option.

The price of gas is a composite made up of several different factors, with the federal gas tax making up less than 20% of what drivers pay at the pump.

Track the location of the Voyager probes, currently between 13 and 15 billion miles away from Earth.

Hear 50 years of iconic hip-hop samples, the genre's foundational looped tracks

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

Mark Twain spent decades feuding with the US Postal Service, convinced its costs and regulations were bureaucratic overreach.

Tattoos remain visible on your skin thanks to immune cells called macrophages

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

Listen to an in-depth conversation on the links between Parkinson's disease and herbicide exposure and the challenging pace of scientific investigation.