The Alhambra’s medieval water system powered a palace-city

The Maya built their cities with advanced engineering

Maya cities featured pyramids, palaces, causeways, ball courts, and water-management systems that were engineered to support large populations—often tens of thousands—without the use of metal tools, draft animals, or wheeled transport.

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 water towers are built that way

How LA brought water to its booming population

By the turn of the 20th century, Los Angeles had grown from a dusty, crime-ridden pueblo into a thriving metropolis. The only problem was that it was growing too fast. Here's the story of how the booming town created a massive water infrastructure to redirect area rivers to its residents.

Niagara's flow is changed artificially to accommodate tourists and power generation

The natural wonder is also the site of great engineering feats, from the Welland Dam that first allowed ships to travel from the upper lakes to the St. Lawrence Seaway, to one of the first hydroelectric dams.

Windmills can be designed to pump groundwater for irrigation or land drainage

A gearbox within the windmill converts the windmill's rotation into the vertical motion of a piston that pushes water up a pipe. It also drives the rotation of an Archimedes screw to move water to higher elevations.

The Middle Ages produced inventions that still our lives today

Far from a “Dark Age,” the medieval era brought about significant innovations—from the printing press and mechanical clocks to navigational tools and early computing devices. This curated list of inventions demonstrates how profoundly medieval creativity has shaped the modern world.

Dubai and Barcelona are examples of smart cities

By integrating technology into public transit, utilities, and other municipal systems, these cities aim to reduce costs and enhance the quality of life for their residents. Some of these technologies include adaptive lighting, parking sensors, and underground waste systems.

During the Medieval Period, urban populations grew significantly

As workers moved from fields to cities throughout the era, large metropolises of enduring strategic importance were formed from Paris, France, to Baghdad, Iraq.

Medieval hospitals existed centuries before modern medicine

Long before modern healthcare, medieval Europe established hospitals that served multiple roles, including religious, social, and medical purposes. This podcast explores how institutions like Siena’s Ospedale di Santa Maria della Scala supported urban and rural communities for centuries.

Spanish Colonial Revival favors red clay roofs, white stucco, decorative ironwork

The style recalls the motifs of structures in both Europe and in colonial Spain. Beyond clay roofs and stucco, the design also showcases arches and arcades, painted tiles, towers, and more.

Ingenuity and advanced engineering have allowed trains to overcome extreme landscapes

The Jungfrau Railway utilizes electric trains powered by hydroelectric energy to ascend the Swiss Alps, while Poland's Elbląg Canal hauls ships along cable-powered tracks driven by waterwheels. Germany's Wuppertal monorail navigates bends as it glides over a river valley, and New Mexico's Holloman High-Speed Test Track can achieve speeds of Mach 8.6 for rocket sleds.

Watch Mediterranean power shift over millennia with this animated map

The ancient Mediterranean holds a vast amount of history; from Egypt to Rome, the coasts of this sea are home to some of the most advanced ancient civilizations. This video displays on a map the many different civilizations that rose and fell around the fertile region, from the year 2500 BCE to 0 BCE.

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.

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.

Disney World's Magic Kingdom includes an underground utilidor

Walt Disney viewed everything happening in his parks as a performance and didn't like it when that performance was disrupted by necessary aspects of the park's maintenance, like trash collection. With Florida's Disney World, the company corrected that problem by building a massive area underneath the park to be used as a "backstage."

Sand 'batteries' can store excess electricity from the power grid as thermal energy

Energy collected from solar or wind power is used to heat insulated silos full of sand to temperatures as high as 450 degrees Celsius (842 degrees Fahrenheit), which can be retained for long periods. These thermal energy storage systems can be designed to boil water and generate electricity when needed.

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

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

Greek-Egyptian scientist Heron invented automatic doors for a temple

The doors opened when a fire was lit in front of the temple, causing heat and pressure to build in a nearby vessel that would force its contents into a higher secondary vessel. This secondary vessel would lower, pulling the doors open. When the fire extinguished, the pressure and liquid in the vessel would reverse course, closing the temple doors.

Catalonia and the War of the Spanish Succession

The War of Spanish Succession (1702-1715) was an international and civil war that reshaped Europe’s political landscape and brought Catalonia under Spanish rule. Created by the Museum of the History of Catalonia in Barcelona, this virtual exhibit guides readers through the 13-year war with a specific eye for its effects on Catalonia. Galleries of artwork from the period on the right-hand side of the page help immerse visitors in the history.

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

Geological features on Mars' surface provide evidence of massive past flooding

The presence of river valleys, enormous canyons, and other structures carved by water on Earth suggests that water flowed abundantly across Mars' surface. The layering of rocks in the walls of these structures indicates the intensity and volume of these flows.

Gulf nations produce about 40% of the world's desalinated water

According to a 2023 report, six Gulf states produced 1.9 trillion gallons of freshwater across more than 400 desalination plants along their coasts. These plants create water suitable for human consumption by boiling saltwater and collecting steam or using high-pressure pumps to push seawater through a filter that only allows water molecules through.

The last Inca grass suspension bridge in Peru

High in the Peruvian Andes, the aging Q’eswachaka bridge sags precariously over the Apurímac River. It has been built and rebuilt continuously for five centuries. Read more about it here.

Video games are helping to preserve cultural heritage sites, further archaeological study

When Carmen Sandiego swept onto the video game scene in 1985, the deluxe version of the game included historic photographs from National Geographic and music from the Smithsonian. Read this article to learn about the overlap between gaming and ancient architecture.

The National Mall's oldest building is the Lockkeeper's House

Built in 1837, the Lockkeeper's House is the oldest structure on the National Mall. It once served the lockkeeper of the Washington City Canal and of an extension of the Chesapeake & Ohio Canal, part of early plans to bring commercial waterways into the capital.

Medieval sword manuals survive—but their techniques are hard to decode

While some knights guarded their combat knowledge, others recorded it in illustrated fighting manuals. Centuries later, scholars struggle to interpret these cryptic texts, revealing how much medieval martial knowledge was lost or obscured over time.

The term 'algorithm' originated from the Latinized name of al-Khwārizmī, a 9th-century mathematician whose works introduced Arabic numerals and the decimal-based numeral system to Europe and whose treatise 'Al-Jabr' gave algebra its name.

Walt Disney's early film 'Alice's Wonderland' was a groundbreaking innovation in the silent film era

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

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.

The history of many kitchen appliances involves unexpected discoveries and applications, including wartime radar turned hamster defroster and replacing an 'ice king' with heat-stealing boxes.

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

Pure water does not conduct electricity because this flow of energy requires the movement of charged particles, and water is a neutral molecule.

Electrical grids worldwide must double their power delivery capacity by 2050 to meet surging demand from AI and electric vehicles.

The use of fungi to detoxify land and water—a process known as mycoremediation—has been used to clean up natural resources affected by the 2025 California wildfires.

Watch how algorithms can be designed to train themselves and self-improve without human input, to the point where the optimized code is too complex for programmers to understand.

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

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.

Planarian flatworms are small, aquatic worms with exceptional regenerative capabilities. When cut, the worms can regenerate multiple bodies in a matter of weeks.

While El Niño moves warm Pacific Ocean waters east along the equator, La Niña moves them west, shifting where rainfall will become more common for months.

Poison ivy was sent to Europe in the 1600s as an exotic, ornamental oddity, where it was purposefully grown in the English royal gardens at Kew, the Faculty of Medicine in Paris, and a few other locations.

The rivalry between Alexander Hamilton and Thomas Jefferson centered on federalism—the question of how much power the federal government should hold relative to the states.

Hotels in Cannes, the glamorous city on the French Riviera, hire hawks to ward off seagulls during the city's famous film festival.

Legendary architect Frank Lloyd Wright designed the SC Johnson headquarters in Wisconsin, aiming to make a cathedral-like workplace

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.

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

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.

Studies suggest when you sleep is as important as how much you get, and syncing with your circadian rhythms may lead to less fatigue and improved long-term health outcomes