City Facts



Modified: 31 May 2023

buildings in a city, cities facts

There are tens of thousands of cities around the world. All of them are unique in their own way, with so much to see and experience within. And here are examples of uniqueness from cities facts.

  1. There are more than 50,000 cities in the world.
  2. Megacities are cities with more than 10 million people living in them.
  3. Tokyo is the most populated city in the world, with more than 38 million people.
  4. New York is the biggest city in the world, with 8,683 km² in area.
  5. The Vatican City is the smallest city in the world, with only 44 hectares in area.
  1. The first cities in history arose in Sumer in Ancient Mesopotamia.
  2. Ancient Egyptian cities were small in comparison to cities of other ancient civilizations.
  3. The ancient Chinese designed their cities to reflect astrological themes.
  4. The ancient Greeks saw cities both as physical places and citizens’ associations.
  5. The Romans founded cities to spread their culture and society to surrounding areas.
  6. European cities shrunk in size and population during the Middle Ages.
  7. The Holy Roman Emperors backed the growth of German cities to weaken the nobility.
  8. The wealth of the Italian city-states jump-started the Renaissance.
  9. Trade and industry fueled the growth of cities during the early modern period.
  10. Deindustrialization posed new challenges to urban life in the late 20th century onward.
  1. The Pacific island country of Nauru is the only country in the world with no cities.
  2. China has the most cities of any country in the world.
  3. Singapore is the smallest city in Asia.
  4. Hong Kong is the world’s richest city.
  5. Yakutsk in Russia is the coldest city in the world.
Table of Contents

Rio de Janeiro’s name means River of January in Portuguese.

It doesn’t actually refer to any of the 200 rivers running through the state. It comes from a misconception made by the sailors who first arrived at Guanabara Bay. They thought the bay was a big river mouth. It was only later that they realized it wasn’t. Despite that, the name stuck for the state and city: Rio de Janeiro.

An aerial view of Rio de Janeiro in the daytime, cities facts
Photo from Pixabay

Mexico City was once the capital of the Aztec Empire.

It went by a different name at the time: Tenochtitlan. At the time, much of modern Mexico City was a lake. Tenochtitlan’s heart stood on an island in the middle of the lake. Floating gardens and artificial islands surrounded the island. The city even had a bigger population than European cities at the time. Aztec records show that before the Spaniards, 300,000 people lived in Tenochtitlan.

The first skyscraper in the world was in Chicago.

This was the Home Insurance Building, built from 1884 to 1885 in Chicago. It stood only 42 meters tall, with 10 floors. It’s small today, but at the time it towered over every other building.

There are always ravens in the Tower of London.

The story goes that Britain will prosper only if there are ravens in the tower. Its origins are unclear, but it seems backed by circumstantial evidence. Shortly before WWII ended, the two ravens in the tower vanished. The tower’s keepers brought in replacements, but it was too late. Some blame the fall of the British Empire after the war on the ravens’ brief disappearance. Today, there are 6 ravens living in the Tower of London, by River Thames in central London.

Delhi and New Delhi are the same city.

New Delhi is actually a district of the city of Delhi. Delhi as a whole is India’s capital, but New Delhi has government buildings. These are Parliament House, the Central Secretariat, and the Supreme Court building.

Moscow’s Kremlin is the only medieval fortress still in use today.

Kremlin is a Russian word that means fortress in a city. In that sense, there are more examples of the Kremlin in Russia. But it’s the one in Moscow that’s usually in mind when talking about the Kremlin.

The Moscow Kremlin at night, cities facts
Photo from Pixabay

Moscow’s Kremlin goes back to the 11th century and grew with the centuries. The castle’s walls include 5 palaces and 4 cathedrals inside. The Grand Kremlin Palace is also inside the walls. It was once the Tsar’s home in Moscow. Now it’s a museum and the home of the Russian President.

Eau de Cologne comes from Cologne, Germany.

Eau de Cologne is generic in written materials for any cologne for men. But there’s a reason for that. Invented and made in Cologne, Germany, it became a highly successful brand. This led to cologne production becoming a major industry in the city since the 18th century. This, in turn, ensured the city’s name becoming the word for liquid scents.

Baghdad was the capital of the Muslim world for 500 years.

Today Baghdad is only Iraq’s capital. But in the 8th century, it was the capital of the Abbasid Caliphate. It ruled over an empire that stretched from North Africa to Persia. It was one of the world’s biggest cities, home to 5 million people. Baghdad was a center of art, learning, and culture. Those 500 years are now known as the Islamic Golden Age. It ended when invading Mongols under Genghis Khan destroyed the city. It was later rebuilt, but much of what the Mongols destroyed was never recovered.

Damascus is a UNESCO World Heritage Site.

The city is one of the oldest in the world, going back to 3000 BC. Its importance comes from its status as a crossroads. Traders and travelers from three continents passed through the city. Those three continents are Europe, Asia, and Africa. Damascus’ importance peaked during the 7th century. The Umayyad Caliphate made it their capital until the Abbasids overthrew them. Even then Damascus remained Syria’s capital, all the way to the present day.

Alexandria in Egypt shares its name with Alexander the Great.

It’s actually kind of ironic that it’s not unique in that sense. You see, Alexander founded more than 70 cities sharing his name. And others more have founded cities in his honor in the millennia since. But only Alexandria in Egypt ever echoed its founder’s fame.

Under the Ptolemaic Dynasty, it was Egypt’s capital. Under them and the Romans, it was a center of art, learning, and culture. The city’s fortunes fell after the Arab Conquest, only to revive in the 19th century. Under the British, it was a major fleet base and port. Though the British have long left Egypt, Alexandria remains Egypt’s primary port.

Helsinki’s sidewalks get heated from underground.

Here’s something warm and thoughtful from cities facts. Helsinki is Finland’s capital, standing along the northern shore of the Gulf of Finland. The country’s latitude means winter gets harsh. Despite this, the streets are almost always clear of ice and snow.

This is thanks to a snowmelt system built under the streets. It melts falling ice and snow and keeps the streets clear. At the same time, this system can keep the streets from getting too hot to walk on in summer.

Kyoto was Japan’s capital for over a thousand years.

Kyoto means ‘capital city’ in Japanese. Settlement began in the 8th century and Kyoto was Japan’s capital until the 19th century.

The Temple of the Golden Pavilion from Kyoto in the daytime, cities facts
Photo from Pixabay

In those more than 1000 years, Kyoto was the heart of Japan’s art and culture. And it remained so even after the capital moved to Tokyo. During WWII, the Allies decided against bombing Kyoto for that reason. They feared the destruction of the city would only stiffen Japanese resistance. Very fortunate too, no matter how we here at cities facts look at it: if the Allies had bombed the city, they’d destroy so much that is irreplaceable.

Seoul’s population density is greater than New York’s.

New York is bigger yet less populated than Seoul. For every square kilometer, there are 16,000 people in Seoul. In contrast, New York only has 10,000 people for every square kilometer.

Chengdu is the source of China’s tea culture.

Tea was first consumed in Chengdu over 3000 years ago. From there the practice spread across China, with Chengdu the heart of the tea trade. Even today Chengdu has more teahouses than any other city in the world.

There’s a spider named after Sydney, Australia.

It’s called the Sydney Funnel Web Spider. It’s also one of the deadliest spiders in the world. The spider’s venom will kill a human being in 15 minutes without medical attention. More than that, its fangs strike hard enough to pierce even protective gloves.

A male Sydney Funnel Web Spider.
Photo from Wikipedia

Pyongyang has the world’s tallest unoccupied building.

The incomplete Ryugyong Hotel stands 330 meters tall in Pyongyang, North Korea. Construction started in 1987 but stopped and resumed several times in the following years. Exterior work finished in 2011, but the lack of funds left its interior unfinished. Between its height and unopened status, it is the world’s tallest unoccupied building.

Kuala Lumpur means river junction in Malay.

This is because the city sits where the rivers Klang and Gombak flow together. This was a deliberate decision during the city’s founding in the 19th century. Supplies would come by the rivers, and cargo shipped away. In addition, tin mines in the surrounding area value-added to this city. On the downside, the city’s position between the rivers made it vulnerable to floods.

Cats have legal protection in Rome.

Starting in 1991, anywhere in Rome with at least 5 cats is a natural urban habitat. All cats living there cannot be chased or taken away. This has led to Rome’s large urban cat population. Present estimates put their numbers at around 300,000 cats in the city.

You can find the world’s oldest restaurant in Madrid.

Madrid’s Sobrino de Botin has served customers since 1725. It’s also expected to continue serving them long into the future. Extra fun fact from cities facts: the restaurant has not put out their kitchen fire since they opened.

The smallest bookstore in the world is in Lisbon.

Lisbon’s Livraria Simão only has enough room for two people inside. Despite this, an estimated 4000 books are on its shelves.

Quebec is the oldest French-speaking community in North America.

The French first arrived at Quebec’s location in 1535. Permanent settlement began in 1608 with the founding of a wooden fort. It provided protection for a trading post set up next to the fort.

The settlement grew over the following centuries. Quebec remained French-speaking even after Britain took over Canada. Today, over 95% continue to speak French.

Miami stands on reclaimed land.

Marshland once made up the ground Miami now stands on. They filled it in with earth as the city grew and developed. Even today Miami remains surrounded by marsh.

The Miami beachfront in the sunlight.
Photo from Pixabay

A cannon gets fired in Cape Town every day.

The tradition goes back to the 19th century. It calls back to when a cannon fired every time a ship entered the city’s harbor. Today the cannon fires only once a day, at noon.

Nairobi was once a camp for railroad workers.

It went by the name of Mile 327 at its founding in 1899. Workers for Britain’s Cape-Cairo railroad used it as a camp and supply base. The name reflected how long the railroad was on reaching the camp. It only became Nairobi after becoming the British provincial capital later in the year.

There are at least 5000 homeless children in Mogadishu.

A sad but undeniable example of cities facts. The children are the legacy of decades of war in Somalia. They live among the city’s ruins and do so under the shadow of various threats. This includes continued fighting, drug use, and sexual abuse. Child labor is a major problem in the city and country alike.

Mecca has never been the capital of any Islamic empire.

There’s something interesting from cities facts, especially considering Mecca has always been the heart of Islam. But none of the Islamic empires had Mecca as their capital.

The first caliphs reigned from Medina. The Umayyads reigned from Damascus. The Abbasids reigned from Baghdad. The Seljuks and Ottomans had several capitals over their empires’ lifetimes. They all contributed to Mecca’s upkeep, though.

The Kaaba in Mecca surrounded by pilgrims.
Photo from Pixabay

Old Jerusalem is a UNESCO World Heritage Site.

Old Jerusalem is a walled district inside the modern city. It covers an area of 1 km² and includes several of the city’s historic sites. These include the Temple Mount, the Church of the Holy Sepulchre, and the Dome of the Rock.

Dubai’s Palm Islands used 94 million m³ of sand.

The Palm Islands are artificial islands built off the waterfront of Dubai in the UAE. The sand used to make them is enough to fill the Empire State Building more than twice over.

There are gold ATMs in Abu Dhabi.

These ATMs convert UAE Dirhams into gold bullion. The customer first puts an equal amount of UAE Dirham into the ATM. The machine then gives the customer one or more gold bars in exchange. Talk about an extravagant example of cities facts.

Volgograd used to have two different names.

At its founding, the city had the name Tsaritsyn. The name changed in 1925 to Stalingrad, in honor of Joseph Stalin. It was at Stalingrad that the German invasion broke in the winter of 1942 to 1943. Krushchev renamed the city Volgograd in 1961. In 2013, the city adopted a measure to rename itself Stalingrad for 9 days a year. Those 9 days celebrate great Soviet victories in WWII.

St. Petersburg’s Hermitage Museum includes cats as part of their official staff.

These cats have the job of keeping the vast museum free of rats. These cats have cat houses and receive benefits from their job. There is an upper limit of 50 cats employed at any time, though. Excess cats get put up for adoption. Prospective owners are always interviewed and checked to confirm their suitability. Their adopted pets come with a certificate indicating their origin from the museum.

A view of the Hermitage Museum in St. Petersburg from the River Neva.
Photo from Wikipedia

Vienna has the title of the City of Music.

This is because many of the greatest classical composers made their careers in the city. Much of this was thanks to the patronage of the Austrian royals and nobles in times past. These graced composers include Mozart, Beethoven, and Haydn among others.

Budapest has a monument to the Holocaust.

It’s found along the banks of the Danube River, next to the Hungarian Parliament. The monument is simple, a series of empty shoes cast from bronze along the water. They’re dedicated to over 3000 people shot by Nazi militia in WWII. Their bodies were then thrown into the river. A solemn example from cities facts, and one we should all take the time to appreciate even if for only a moment.

Jakarta is not a city.

At least when it comes to Indonesian politics and governance. Practically speaking, it is a city. The reason for this is the sheer size of this city. Jakarta covers an area of 661.5 km². This has led to the Indonesian government declaring and treating the city as a province.

China’s oldest airport is in Beijing.

This is the Nanyuan Airport, established in 1910. It is a military airport, with civilian air traffic going to three other airports in the city.

Hong Kong is an archipelago.

Hong Kong is often referred to as a single island, so this fact is usually forgotten. In reality, Hong Kong is an archipelago of 263 islands. Some have development on them with regular ferries to and from the islands. Others are pristine and undeveloped and left all but unreachable.

Macau was the first Asian colony of any western country.

It was also the last they let go of. The Portuguese gained Macau from China in 1557 and returned it in 1999.

Manila’s population density is the highest of any city in the world.

The city covers 42.88 km² of area. And you can find 42,000 people for every square kilometer. That’s over four times the population density of New York.

A view of the city from Manila Bay at night.
Photo from Pixabay

San Francisco had it easy in the Great Depression.

Banks went bankrupt one after another across the USA in the Great Depression. In San Francisco though, not a single bank went bankrupt. In fact, business went well enough that the city built two great engineering feats. Those were the Oakland Bay Bridge and Golden Gate Bridge.

Vancouver once practiced a form of segregation.

West Vancouver is where you can find the high-end residences of the city. At one point in the past, only British citizens resided there. Jews and colored people weren’t allowed to enter the district at all.

Washington DC has the world’s tallest obelisk.

This is none other than the Washington Monument, standing at about 169 meters tall. It was also the tallest building in the world at the time of its completion. It lost that title to the Eiffel Tower on its completion. Regardless, the monument still stands as an iconic location in Washington D.C.

Washington D.C. at night in winter, with the Capitol Building in the center, and the Washington Monument to the left and back.
Photo from Pixabay

Tokyo used to be wood and paper.

This was the case until WWII. Only important buildings like the Imperial Palace and government structures were of stone. This proved disastrous during the war, as wood and paper proved easy to burn. The Allied bombings reduced most of Tokyo to ash by the war’s end. Afterward, the Japanese rebuilt the city with steel and concrete to reduce the risk of fire.

Vladivostok is Russia’s largest port in the Far East.

This is the case for two main reasons. One is because Vladivostok is the eastern end of the Trans-Siberian Railroad. Second is that Vladivostok is ice-free all year round. As a result, 10 million tons of shipping pass through its port every year. It is also the base for Russia’s Pacific Fleet.

Venice is dying.

Dying in the sense that fewer and fewer people live in the city. In the 1970s an estimated 120,000 people lived in the city. Today though only 55,000 people live in the city. Experts fear that by 2030 Venice will have become a ghost town visited by tourists. A sad and grim prospect of an example of cities facts, to be sure.

New York is the most diverse of any city on Earth.

In language alone, there are at least 800 distinct languages spoken in the city. English is actually a minority language in New York. Only 4 out of every 10 households in the city use it as a primary language.

New York’s skyline in the sunlight.
Photo from Pixabay

Florence was the heart of the Renaissance.

Many of the bright minds of the Renaissance came from Florence. These include great artists like Leonardo Da Vinci and Michelangelo. Political theorist Machiavelli came from Florence, as did the powerful Medici family. The latter left their mark on Europe for centuries even after the Renaissance. Definitely an example of cities facts that Florentines can honestly take pride in.

Marseille gave its name to France’s national anthem.

Here’s an especially historic example of cities facts. The national anthem first went by a different name. But the first to sing it was a group of volunteers arriving in Paris from Marseille. This caught the public’s and their fellow soldiers’ attention. From then on, the French national anthem shared the city’s name: La Marseillaise.

Joan of Arc made her mark on history at Orleans.

Orleans is a city in central France, along the River Loire. It was also there that the French made their last stand in the Hundred Years War. Starting in 1337 the English Plantagenets fought to win the French throne. The French Valois stood against them, but by 1428 it seemed the English had all but won. This changed when Joan and her allies arrived at Orleans. Only 9 days after her arrival, the English retreated in defeat. The war continued until 1453, but only in France’s favor after the victory at Orleans.

Los Angeles is the world’s entertainment capital.

Unsurprising, seeing as Hollywood is in Los Angeles, after all. Hollywood aside, Los Angeles also has over 100 museums dedicated to various subjects. The Walk of Fame is also in Hollywood, among other sights. Tourists coming to the city can choose between over 1000 hotels to stay in.

Las Vegas uses recycled water in its fountains and artificial lakes.

The recycled water starts as wastewater from baths and kitchens. In this state, it’s called greywater. It’s filtered and disinfected before getting used for waterworks. This way Las Vegas conserves water limited by the desert conditions of the state. Despite how it might sound, it’s not that disturbing an example of cities facts.

Houston has the world’s largest medical center.

The Texas Medical Center in Houston covers over 400 hectares. 54 different medical institutions stand on its grounds. An estimated 7.2 million people visit the center every year, both patients and their families.

7-11 started in Dallas.

They started out selling ice in Dallas. In 1927, they branched out and started selling groceries. Then they started selling gasoline in 1928. 7-11 added more goods and services over the decades. The iconic Slurpee first began to sell in 1965.

The British captured Buenos Aires in 1806.

At the time the Napoleonic Wars raged across Europe. The British took Buenos Aires as part of a campaign against Napoleon’s Spanish allies. They only held it for two months, though. The militia led by Santiago de Liniers arrived and forced the British to abandon the city.

Bangkok is also commonly called Krung Thep in Thailand.

It means City of Angels in the Thai language. Bangkok is actually a foreign name, but one of unclear origin. Don’t be surprised, but the actual full ceremonial name for Bangkok is Krungthepmahanakhon Amonrattanakosin Mahintharayutthaya Mahadilokphop Noppharatratchathaniburirom Udomratchaniwetmahasathan Amonphimanawatansathit Sakkathattiyawitsanukamprasit. (Wow, now try reading that out loud.)

A time lapse photograph of Bangkok at night.
Photo from Pixabay

Chelyabinsk was once called Tankograd in the past.

It means Tank City in Russian. The reason for this goes back to WWII and the German invasion. Chelyabinsk was the center of the Soviet’s tank industry. At least 18,000 tanks came from Chelyabinsk, along with almost 50,000 diesel engines. After the war ended, Chelyabinsk returned to civilian production. Tractors and other agricultural machines became the city’s new focus. Talk about an imposing example of cities facts.

Guangzhou is one of China’s oldest cities.

The first settlement on the city’s site goes back to the 2nd century BC. Called Panyu at the time, it was a base for the Qin Dynasty’s army. It later became the provincial capital under the Han Dynasty.

Even at the time, Guangzhou was a major port and trading hub. Traders from all over China, the Middle East, and even as far as Rome came to the city. This was not always appreciated though. In the 8th century AD, anti-Tang rebels killed thousands of foreigners in Guangzhou. Despite that episode, Guangzhou remains one of China’s main ports to the present day.

Wuhan is the most populated city in central China.

At present, Wuhan boasts a population of 11 million, classifying it as a megacity. Its position in central China has also made it a travel hub for centuries. Before modern times, travelers came either overland or by boat. Two rivers pass by the city, the Yangtze and the Han. Today dozens of railways go through the city, bringing more travelers with them.

The Dazu Rock Carvings are in Chongqing.

The carvings are sculptures depicting Buddhist, Taoist, and Confucian figures. They go back to the 7th century when work began under the Tang Dynasty. Work continued past the dynasty’s fall, all the way to the Song Dynasty. The carvings are in Chongqing’s Dazu district.

The heaviest building in the world is in Bucharest.

Bucharest has the Palace of the Parliament, and which weighs over 700,000 tons. Nicolae Ceaușescu ordered it built in the Communist era. As the name shows, it houses Romania’s Parliament. The building also includes 3 museums and an international conference center.

There are thermal springs under Sofia.

They’re not developed though. These thermal springs are in the countryside around the city. There are fountains tapping into the springs, though. Visitors are free to drink from these fountains. The minerals in the water have many health benefits for the human body.

Athens is Europe’s oldest capital city.

The city goes back to the 14th century BC. In that time it has been under every kind of government in history. Athens experienced monarchy, aristocracy, oligarchy, and tyranny. It has even experienced Communism. Today though it is a democracy, as modern Greece’s capital. Very fitting too, as democracy first appeared in Athens thousands of years ago.

Athens’ Acropolis in a half-light.
Photo from Pixabay

WWI started in Sarajevo.

In 1914, Sarajevo was part of the Austro-Hungarian Empire. This caused resentment in Serbia, as plenty of Serbs lived in Sarajevo. In June of that year, Serbia nationalist Gavrilo Princip shot Archduke Franz Ferdinand. The archduke rode an open car with his wife, and both died from the shots. Within a month of their deaths, WWI began and did not end for four years.

Istanbul was once named Constantinople.

It means the City of Constantine. That name honors Emperor Constantine of Rome, who founded the city. After Emperor Theodosius’ death, the Roman Empire divided into two. Constantinople then became the capital of the Eastern Roman Empire. This led to the city getting known as the Second Rome.

Tripoli is in North Africa.

One common misconception is that both Libya and Tripoli are in the Middle East. They’re actually in North Africa, along the Mediterranean coast.

Tunis stands where Carthage once was.

Carthage was an ancient Phoenician city in North Africa. It was also Rome’s rival. This led to three wars, the last of which ended with Rome destroying Carthage. Berber tribes later settled the ruins. It stayed small until the Arab conquest when the city began to grow into the city it is now today.

Timbuktu was a center of trade and learning during the Middle Ages.

The city was the capital of the Songhai Empire in the Middle Ages. Islamic scholars gathered in the city’s university, one of the biggest in the world. Traders from across west Africa passed through the city. Among their merchandise were cloth, gold, ivory, and slaves.

The Great Pyramid is at Giza.

Giza is an Egyptian city about 5 km southwest of Cairo. It is the third-largest city in Egypt. It’s also where the last wonder of the ancient world stands. Built in the 2nd millennium BC, the Great Pyramid stands 147 meters tall.

The Great Pyramid of Giza in the sunlight.
Photo from Wikipedia

There are mud volcanoes near Baku.

Baku is Azerbaijan’s capital, in the Caucasus, along the Caspian Sea. The region is rich in fossil fuels, such as oil and gas. Some of that gas leaks through the muddy ground near the city. This sometimes causes eruptions of mud into the air. Even rarer is when the gas ignites. This event causes jets of flame up to a kilometer in height.

Kiev has the world’s deepest metro station.

Kiev’s Arselna Station is 105 meters underground. They go back to the 1960s and include nuclear shelters from the Cold War.

More Belorussians live in Minsk than anywhere else in their country.

Outside of Minsk, the population density of Belarus is 46 people per square kilometer. In Minsk though, there are 4,633 people per square kilometer.

Stockholm has the world’s longest art gallery.

And it’s not even part of a formal museum. Instead, Stockholm’s subway system is the art gallery. Over 150 artists lined the walls of the subway with their artwork ever since the 1950s. These include classic forms like paintings and sculptures, as well as street art. This makes for over 100 km of artistically decorated tunnels.

Oslo was once called Christiana.

King Christian IV renamed the city after himself after a fire destroyed old Oslo in 1624. It kept that name until Norway became a separate nation. This was at the start of the 20th century. The government then decided to return the city’s name back to Oslo.

Reykjavik is safe enough that babies can sit alone in the open.

It’s a common sight in Reykjavik to see a baby in a stroller standing alone on a street. This is to let them enjoy the fresh air and sunlight. Usually, it’s done while the parents go shopping for groceries. A marvelous example of cities facts, to be sure.

Prague has a simple flood warning system.

The river Vltava flows through Prague. One of the bridges crossing it is the Charles Bridge. The sculpture of a man’s head is in front of one of the walls next to the bridge. It faces the river. Should the water ever reach the sculpture, then there’s a danger of a flood.

Old Warsaw is a reconstruction.

The original Old Warsaw got destroyed during WWII. After the war, the Polish government used pre-war records as a template. That template allowed Old Warsaw to rise again as it once was.

The ruins of Old Warsaw after WWII, cities facts
Photo from Wikipedia

Berlin has more bridges than Venice.

Despite not standing on water, Berlin beats Venice out on this. Venice only has 409 bridges. In contrast, Berlin has 1,700 bridges.

Shanghai has the world’s longest metro system.

Over 600 km of tunnel and tracks run under Shanghai. 393 stations across the city allow access to and from the metro.

Paris has an underground lake.

It’s found under the famous Opéra de Paris. The lake is artificial, formed from draining the swampy ground where the opera stands. Approximately 10,000 m³ of water is in the lake. It’s not open to the public, though. Instead, it’s used by the Paris fire brigade for training purposes.

Vesuvius’ eruption caught Pompeii by surprise.

Pompeii’s citizens had no idea they were in any danger. Scientific study shows that Vesuvius last erupted 1,800 before it destroyed Pompeii. So as far as its citizens knew, Vesuvius was only a mountain.

Honolulu is next to Pearl Harbor.

Pearl Harbor is the US Navy’s main base in the Pacific. On December 7, 1941, Japan attacked Pearl Harbor. This dragged America into WWII. Honolulu was not unaffected by the attack. 68 civilians died in the attack from stray fire.