Rome, the Eternal City

Imagine a city so old that it has been busy for almost 2,800 years without ever taking a break. While other ancient cities crumbled into sand and silence, this one kept going: kids still splash in fountains built for emperors, buses rumble past temples older than most countries, and people drink water that travels through a stone tunnel finished more than 2,000 years ago. Welcome to Rome, the city Romans themselves nicknamed the Eternal City, because they honestly believed it would last forever. So far, they have been right.

Here is the first secret most visitors never learn: Rome is not one city. It is many cities stacked on top of each other like a giant lasagna. Under the modern streets lie medieval streets, and under those lie ancient Roman streets, sometimes nine meters down, about as deep as a three-story building is tall. Dig almost anywhere and you will bump into something amazing.

In this book we will explore Rome like detectives. We will find self-healing concrete, a hole in a roof that was put there on purpose, elevators built 1,900 years before electricity, and cats living in the ruins of ancient temples. Ready? Let's go.

Every city has a story about how it began, but Rome has something stranger: an actual birthday. Romans decided long ago that their city was founded on April 21 in the year 753 BC, and modern Romans still throw a giant birthday party every April 21, with parades and people dressed in togas. Imagine your hometown having birthday cake that is 2,800 candles tall.

The legend says the city was started by twin brothers named Romulus and Remus, who as babies were found by a she-wolf who kept them safe and fed until a kind shepherd took them in. When they grew up, Romulus founded a city on a hill and named it after himself: Roma. That is why you will see statues of a wolf with two babies all over the city. It is Rome's oldest logo.

The real story is that farmers and shepherds settled on seven hills beside the Tiber River, where there was fresh water, good soil, and a shallow place to cross. Those seven hills still have their ancient names today, like the Palatine and the Capitoline. In fact, the word capitol, as in a capitol building, comes straight from the Capitoline Hill.

Here is a mystery that puzzled scientists for centuries: why are so many Roman buildings still standing after 2,000 years, while modern concrete sidewalks crack in twenty? The answer starts inside a volcano.

Roman builders discovered that a special volcanic ash, called pozzolana, found near Naples and around Rome, could be mixed with lime and water to make concrete that was astonishingly tough. When the ash and lime meet water, they grow microscopic crystals that lock everything together like millions of tiny interlaced fingers. Roman engineers did not know about crystals or chemistry, but they were brilliant observers. They noticed what worked, wrote down recipes, and kept improving them, the same way you might perfect a cookie recipe by testing batch after batch.

They became so confident in their concrete that they did something wild: they poured it into the sea. Roman harbors had huge concrete blocks sitting in salt water, which destroys most modern concrete in a few decades. An ancient writer named Pliny the Elder even bragged that Roman sea walls became a single stone mass, stronger with every passing day. For a long time, scientists thought that was just boasting. It wasn't.

In 2017, scientists studied pieces of 2,000-year-old Roman harbor walls and found something amazing: the seawater had not been destroying the concrete at all. It had been feeding it. Salt water seeping into the concrete triggered chemical reactions that grew rare, tough crystals inside the cracks, so the walls actually got stronger as they aged. Modern concrete gets weaker in the ocean. Roman concrete works out and builds muscle.

Then, in 2023, researchers at MIT cracked an even bigger secret. Scientists had long noticed little white lumps of lime scattered through Roman concrete and assumed they were mistakes, like lumps in badly mixed pancake batter. They were not mistakes. They were a repair kit. The Romans mixed their concrete hot, using a fiery reaction that left these lime lumps behind on purpose.

Here is the magic: when a tiny crack forms and rainwater trickles in, the water dissolves a bit of lime, which then hardens into new stone and seals the crack shut. The building heals itself, like your skin closing over a scrape. In laboratory tests, cracked Roman-style concrete repaired itself within weeks. Engineers today are now copying a 2,000-year-old recipe to build things that last longer.

In the middle of Rome stands a building that looks like it was dropped there by time travelers. It is called the Pantheon, which means temple of all the gods, and it was completed around the year 126, when the emperor Hadrian ruled. It has been in continuous use for about 1,900 years, which makes it one of the best-preserved ancient buildings on Earth.

Walk up to it and you pass sixteen granite columns, each about 12 meters tall and weighing around 60 tons, as heavy as ten elephants stacked together. Here is the astonishing part: those columns were quarried in Egypt, floated down the Nile River, shipped across the Mediterranean Sea, and hauled through Rome, all without a single truck or crane engine. Then you push through giant bronze doors that are original ancient Roman doors, still swinging on their hinges after all these centuries.

But the real showstopper is above your head. Step inside, look up, and you will see a vast gray dome curving over you like a stone sky, with a perfect circle of real sky glowing at the very top. First-time visitors almost always gasp. And that dome holds a world record.

The Pantheon's dome is about 43 meters across, wider than a basketball court is long, and after 1,900 years it is still the largest unreinforced concrete dome in the world. Unreinforced means there is no steel skeleton hiding inside, just concrete, holding itself up through pure clever design. No one, ancient or modern, has ever built a bigger one without metal reinforcement.

How did they do it? The builders made the dome like a smart layer cake. At the bottom, where the walls are six meters thick, they mixed heavy stone into the concrete. Higher up, they switched to lighter and lighter rock, finishing with pumice, a volcanic stone so full of air bubbles it can float in water. The dome literally gets lighter as it rises. The proportions are perfect too: the dome is exactly as tall as it is wide, so a giant ball would fit precisely inside the room.

At the very top is a round opening called the oculus, Latin for eye, about eight meters wide. It is not broken; it was built that way, as the room's only window and sunbeam clock. Yes, rain falls in, and the floor secretly slopes toward hidden drains, ready for showers since ancient times.

A giant city has a giant thirst. Ancient Rome grew to about one million people, and you cannot give a million people baths, fountains, and drinking water from one muddy river. So Roman engineers built aqueducts: artificial stone rivers that carried fresh spring water from distant hills straight into the city.

Eventually Rome had eleven aqueducts stretching hundreds of kilometers in total. Here is the surprise: those famous stone bridges with rows of arches are only a small part of the system. Most of an aqueduct ran hidden underground, in tunnels carved through hills. The arches only appeared where the water needed to cross a valley without dropping too low.

And here is the genius part: no pumps. Not one. The whole system ran on gravity alone. Engineers sloped the channels ever so slightly, sometimes dropping only about 30 centimeters, one ruler length, for every kilometer traveled, so the water flowed calmly for days across the countryside. To measure such tiny slopes, surveyors used a water-filled leveling tool called a chorobates, sort of an ancient spirit level the size of a park bench. Getting it wrong by a fingertip per kilometer could stop the water completely. They almost never got it wrong.

Rome may be the only city on Earth where the drinking fountains are 2,000 years in the making. One ancient aqueduct, the Aqua Virgo, finished in 19 BC by a Roman named Agrippa, has been delivering water to Rome almost continuously ever since. Water still flows along its ancient route today and pours out of some of the most famous fountains in the world. Think about that: the pipes are older than the calendar we use.

Modern Rome is dotted with around 2,500 small public drinking fountains that run day and night with cold, clean, free water. Romans call them nasoni, which means big noses, because each one has a curved metal spout that looks like a long nose. Here is a trick every Roman kid knows and most tourists never learn: block the end of the nose with your finger, and the water shoots up through a small hole on top of the spout, turning the fountain into a perfect water arc for drinking, no cup needed.

The water is not wasted, either. The constant flow keeps the pipes clean, and much of the runoff gets reused. In a Roman summer, a nasone is pure treasure.

The Trevi Fountain is Rome's most theatrical fountain: a whole palace wall exploding into carved sea horses, tritons, and waterfalls, with the ocean god Oceanus riding a shell-shaped chariot in the middle. It is fed by water from the route of the ancient Aqua Virgo aqueduct, so the show has been running on 2,000-year-old plumbing.

There is a famous tradition here. Stand with your back to the fountain, hold a coin in your right hand, and toss it over your left shoulder into the water. Legend says that guarantees you will return to Rome one day. Millions of visitors do it every year, and the coins really add up: on a busy day, thousands of euros splash into the fountain, and in a year the total can pass one and a half million euros.

So who gets all that treasure? Here is the wonderful secret: nobody keeps it for profit. City workers sweep the coins out with long brushes and vacuum machines, and the money goes to a charity called Caritas, which uses it to run food programs and help people in Rome who have fallen on hard times. Every wish tossed into the water becomes somebody's supper.

The Colosseum is the most famous stadium ever built, and it opened in the year 80, about 1,945 years ago. It could hold around 50,000 spectators, roughly the same as many modern football stadiums, and it solved the same problems modern stadiums face: how do you get a whole city's worth of people in and out without a gigantic traffic jam?

The Roman answer was brilliant. The building has 80 arched entrances at ground level, and 76 of them were numbered. Spectators held tickets, small tokens of pottery or bone, marked with an entrance number, a level, and a section, and followed the numbers to their seats, exactly like finding your seat at a stadium today. Thanks to all those arches and cleverly placed staircases, the crowd could reportedly empty the whole building in around fifteen minutes.

The outside walls used a stone called travertine, held together with iron clamps instead of mortar. Centuries later, people pried out much of the iron to reuse it, which is why the walls are covered in mysterious little holes, like a giant stone whack-a-mole board. The building still stands anyway. Roman engineering left plenty of margin for error.

Here is something most visitors never realize: the Colosseum had elevators, about 1,800 years before electric ones were invented. Beneath the arena floor lay a hidden two-story basement called the hypogeum, a maze of corridors, cages, ramps, and machinery, like the backstage of a giant theater.

Built into that maze were more than two dozen lifting platforms. Each one worked with ropes, pulleys, and a capstan, a big vertical wooden winch that workers pushed around in circles like a merry-go-round. As they walked, the ropes wound up and the platform rose smoothly until it reached hidden trapdoors in the arena floor. Suddenly, to the crowd's amazement, scenery, props, or wild animals appeared as if by magic from below: a whole forest of trees could sprout in minutes for an animal show, or a painted mountain could rise into view.

Modern engineers tested the design by building a working replica of one lift right in the Colosseum, using only Roman-era techniques. It worked beautifully, raising hundreds of kilograms with a handful of people pushing the capstan. The lesson hiding underground is a great one: you do not need electricity to be clever. The Romans ran their special effects on muscle, ropes, and mathematics.

Sitting in an open stadium under the blazing Italian sun for hours would roast anyone. So the Colosseum came with something even many adults have never heard of: a gigantic retractable roof, invented almost 2,000 years before modern stadiums got theirs.

It was called the velarium, and it was made of huge canvas awnings, not solid panels. Around the top rim of the Colosseum stood about 240 wooden masts, fitted into stone sockets you can still see today. From these masts, a web of ropes stretched over the seating bowl, and enormous strips of sailcloth could be rolled out along the ropes to shade tens of thousands of spectators, while leaving the center open to the sky.

Now the best detail of all: who do you call when you need experts at handling masts, ropes, and giant sheets of canvas in the wind? Sailors. The Roman navy kept a special detachment of sailors from the fleet at Misenum stationed in Rome, and their job was to rig and operate the velarium, hauling lines and trimming the great sails of the stadium as if the Colosseum were a ship. On windy days, the whole roof could be reefed in, exactly like sails in a storm.

The Romans were the greatest road builders of the ancient world. At the empire's height, they had laid over 80,000 kilometers of paved highways, enough to circle the entire Earth twice, plus hundreds of thousands of kilometers of smaller roads. Some of those roads are still there, and you can still walk on them.

A Roman road was built like a sandwich. Workers dug a deep trench, then added layers: big stones at the bottom for a foundation, then smaller stones and gravel, sometimes mixed with that famous Roman concrete, and finally tight-fitting paving stones on top. The surface was gently curved, higher in the middle, so rainwater rolled off into ditches on the sides instead of puddling. Some roads were a meter thick or more. That is why they lasted twenty centuries.

Roman surveyors were obsessed with straight lines, because straight is the shortest distance and armies, mail carriers, and merchants were all in a hurry. Using a tool called a groma, a cross of sticks with hanging weights, they sighted perfectly straight paths across the landscape for kilometer after kilometer. The Appian Way, begun in 312 BC, runs so straight in places that its first stretch barely bends for tens of kilometers.

You have probably heard the saying all roads lead to Rome. Here is the surprise: it was almost literally true, and there was even an official spot where they all led to. In 20 BC, the emperor Augustus set up a gilded bronze column in the Roman Forum called the Milliarium Aureum, the Golden Milestone. It was treated as the symbolic point where every great road of the empire began, kilometer zero of the Roman world. A fragment believed to be from its base still sits in the Forum today.

Along every major road, the Romans planted milestones: stone pillars, often taller than a grown adult, marking each Roman mile. A Roman mile was mille passus, one thousand paces, about 1,480 meters, and the word mile comes straight from that Latin phrase. Milestones told travelers how far they were from Rome and sometimes who built or repaired the road, like a signpost and a plaque in one.

Thanks to roads and relay stations with fresh horses, official messengers could cover 80 kilometers or more in a day. News, letters, recipes, and ideas raced across three continents on stone sandwiches. Roads did not just carry Romans; they carried the whole Roman world.

Long before printing presses, television, or the internet, Rome had daily news. Starting in 59 BC, by order of Julius Caesar, the government began publishing the Acta Diurna, which means Daily Acts or daily doings. Many historians call it the world's first newspaper.

It was not printed on paper, because printing had not been invented in Europe yet. Instead, the news was written or carved onto whitened boards and posted in busy public places like the Forum, the way a school posts announcements on a bulletin board. Anyone walking by could stop and read the day's headlines. And the headlines were surprisingly familiar: government decisions, court news, important speeches, birth and marriage announcements, and results from the games, including the chariot races that Romans followed as passionately as fans follow football teams today.

Here is the clever part: the news did not stay in Rome. Scribes copied the boards by hand, and the copies traveled out along those excellent Roman roads to generals, governors, and wealthy readers across the empire. A person living weeks of travel away could still catch up on the capital's news, delivered by the ancient world's version of a paper route stretching thousands of kilometers.

Quick quiz: when were apartment buildings invented? Not in New York, and not in the last few centuries. Ancient Rome was so crowded that Romans invented the apartment block around 2,000 years ago. They called one an insula, which means island, because each building stood like an island surrounded by streets.

Rome was likely the first city in history to reach one million people, a size London would not match until around the year 1800. A million people cannot all have houses with gardens, so Rome built upward. Insulae rose five, six, even seven stories, and city records from late antiquity counted tens of thousands of apartment blocks compared with fewer than two thousand private houses. Most Romans were apartment dwellers, just like people in big cities today.

Here is the funny twist: Roman buildings were upside down compared with ours. Today, penthouses at the top are the fanciest homes. In Rome, the ground floor was the luxury level, with shops facing the street and the biggest apartments, because there were no elevators and every bucket of water had to be carried upstairs. The higher you lived, the cheaper, smaller, and creakier your room. Emperors even passed height limits to keep builders from stacking floors too high.

On a cold winter morning, would you rather step onto icy tiles or a toasty warm floor? The Romans chose warm, and they engineered it. Their invention was called the hypocaust, which means fire underneath, and it was central heating almost 2,000 years before modern radiators.

Here is how it worked. Builders raised the floor of a room on dozens of short brick pillars, leaving a hollow space below. A furnace at one side, kept burning by enslaved workers and servants who fed it wood, sent hot air and smoke flowing through that space under the floor, and sometimes up through hollow tiles hidden inside the walls. The floor above grew deliciously warm, the walls gently toasty, and the smoke escaped through vents. Warm floors, warm walls, no fire in the room itself.

The hypocaust made possible one of Rome's favorite places: the public baths. The enormous Baths of Caracalla could welcome about 1,600 bathers at a time, with hot pools, warm rooms, cold plunges, gyms, gardens, and even two libraries, one for Latin books and one for Greek. For a small coin, an ordinary Roman could spend the afternoon soaking like an emperor. It was part swimming pool, part spa, part community center.

Picture a lunch counter with big pots of hot food sunk into the countertop, colorful pictures of the menu painted on the front, and customers eating standing up because they are in a hurry. A modern food court? No: a Roman thermopolium, the ancient world's fast food restaurant.

Most apartment dwellers in Roman cities had no proper kitchens, since open cooking fires in tall wooden buildings were a terrible idea. So Romans ate out constantly. In the city of Pompeii, which was buried and preserved by the eruption of Mount Vesuvius in the year 79, archaeologists have found around 80 of these snack bars. Each has a masonry counter with round holes where deep jars called dolia held food and drink: things like lentils, spiced wine, cheese, and stews.

In 2020, archaeologists in Pompeii unveiled a spectacularly preserved thermopolium with its paintings still bright after nearly 2,000 years, including a picture of a rooster and ducks, probably advertising what was cooking, the ancient version of a menu with photos. Inside the jars, scientists found traces of duck, goat, pig, fish, and snails. So the next time you grab a quick bite at a counter, remember: Romans beat you to it by two millennia.

Open any calendar and you are looking at a Roman invention. By 46 BC, Rome's old calendar had drifted hopelessly out of step with the seasons, with harvest festivals landing nowhere near the harvest. Julius Caesar, advised by an astronomer from Alexandria named Sosigenes, decided to fix it once and for all.

First came the strangest year in history: to reset everything, 46 BC was stretched to about 445 days long. Romans called it the year of confusion, and you can see why. Then the new Julian calendar began: twelve months, 365 days, and, brilliantly, an extra leap day every four years to match the fact that Earth's trip around the sun takes about 365 and a quarter days. Sound familiar? That is essentially your calendar.

The month of July is named for Julius Caesar himself, and August honors his heir, the emperor Augustus. Caesar's calendar ran the Western world for over 1,600 years, until 1582, when Pope Gregory XIII made one tiny repair: the year is actually a few minutes short of 365.25 days, so ten extra days had piled up and the leap year rules were slightly tightened. Everything else about your calendar is pure ancient Rome.

Even if you have never visited Rome, Rome has visited you. It is hiding in your mouth. English borrows enormous numbers of words from Latin, the language of the Romans. Ever used a bonus? Latin. Been to a circus, watched a video, needed an exit, or studied science? Latin, Latin, Latin, Latin. Whole languages, including Italian, Spanish, French, Portuguese, and Romanian, grew directly out of Latin, which is why they are called Romance languages: languages from Rome.

Roman numerals are hiding everywhere too. Look for them on fancy clock faces, in movie credits, on the Super Bowl logo, and in the names of kings and queens. When you see the year MMXXVI carved on a building, you are reading exactly the way a Roman would have read it.

And in Rome itself, the ancient government never quite left. The letters SPQR stood for Senatus Populusque Romanus, the Senate and People of Rome, and it was the official signature of the ancient Roman state. Walk through Rome today and you will find SPQR stamped on manhole covers, drinking fountains, buses, and rubbish bins, because it is still the official emblem of the city government. Ancient Rome literally signs the sewer lids.

In the middle of Rome's traffic sits a sunken square called Largo di Torre Argentina, holding the ruins of four temples, some more than 2,300 years old. This is also the area where Julius Caesar's senate once met. It is one of the most important archaeological sites in the city. And it is ruled by cats.

When the ruins were excavated in the late 1920s, Rome's street cats moved in immediately. Warm sun-baked stones, no cars, endless hiding spots between ancient columns: cat paradise. Kind Romans, nicknamed gattare, or cat ladies, began feeding them, and eventually a full cat sanctuary grew right inside the ruins. Today volunteers care for roughly 150 cats, feeding them, giving them medicine, and finding homes for many.

Here is the wonderfully official part: Rome's city government has declared its free-roaming cats part of the city's bio-cultural heritage, meaning the cats are legally recognized as a protected piece of Rome's living history, like a monument with whiskers. A cat born among Rome's ruins has a right to live there undisturbed. So at Torre Argentina, tourists lean over the railings to photograph 2,300-year-old temples, and the cats doze on the ancient stones, completely unimpressed by all the history beneath their paws.

Here is a fact that sounds like a riddle: inside the city of Rome there is an entire separate country. It is called Vatican City, and it is the smallest country in the world, only about 0.44 square kilometers, small enough to fit inside New York's Central Park about eight times. You could stroll across the whole nation in about twenty minutes.

Tiny as it is, it is a real country, home to the Pope, the leader of the Catholic Church, and only a few hundred residents. It has its own passports, its own stamps and post office, famous for being speedy, its own euro coins that collectors hunt for, its own tiny railway station, and its own newspaper and radio. It is guarded by the Swiss Guard, soldiers from Switzerland who wear spectacular striped uniforms of blue, red, and yellow, a tradition going back to the year 1506.

At its heart rises St. Peter's Basilica, one of the largest churches on Earth, its dome soaring about 136 meters, taller than a 40-story building. Michelangelo, in his seventies, helped design that dome. Nearby stand the Vatican Museums, kilometers of corridors so packed with art that seeing everything would take days. And one ceiling there is the most famous in the world.

In 1508, the Pope asked an artist named Michelangelo to paint the ceiling of the Sistine Chapel. Michelangelo protested that he was a sculptor, not a painter. Then he climbed the scaffolding and, over four years, created what many call the greatest painting ever made: hundreds of figures telling stories from the Bible across roughly 500 square meters of ceiling, bigger than a basketball court, all painted by hand above his own head.

Here is a myth to bust for any grown-ups nearby: Michelangelo did not paint lying down. He designed a special standing scaffold and worked with his head tilted back and his arm raised for hours a day. It was so uncomfortable that he wrote a grumpy poem to a friend complaining that his beard pointed at heaven and paint dripped onto his face.

He painted in fresco, brushing color onto fresh wet plaster so the painting became part of the wall itself, which means he had to work fast and get it right before the plaster dried. Centuries of candle smoke slowly darkened the ceiling, until a famous cleaning, finished in the 1990s, revealed Michelangelo's true colors: brilliant greens, oranges, and violets that astonished the world all over again.

Remember how Rome is layered like a lasagna? That creates a very Roman problem: it is almost impossible to dig anywhere without discovering something precious. This makes building a subway spectacularly slow. Rome has only a few metro lines, while other capitals have a dozen, and the newest one, Line C, has taken decades, partly because archaeologists must carefully examine what the tunnels uncover.

And what treasures they find! While digging Line C, workers and archaeologists discovered an ancient military barracks with dozens of rooms and mosaic floors, a Roman house with a marble-lined bathing pool, ancient peach pits and farm tools, and even a commander's lavish quarters, all sleeping quietly meters below the traffic. At the San Giovanni metro station, the builders had a wonderful idea: instead of hiding the finds, they turned the station itself into a mini museum, where displays of discovered treasures greet commuters on their way to the train.

Rome also collects monuments from elsewhere. The city holds more ancient Egyptian obelisks than any city in Egypt, thirteen ancient obelisks in all, brought by emperors as spectacular souvenirs. In Rome, even a ride to school or a walk to the shops passes through thousands of years of buried wonders.

Our journey is ending, but here is the secret that ties everything together: Rome is not amazing because it is old. Plenty of things are old. Rome is amazing because it is full of ideas that were so good they never stopped working. Concrete that heals itself. A dome that has held itself up for 1,900 years. Water that still flows by gravity alone. A calendar so clever you are living inside it right now.

None of it was magic. Every wonder in this book began with a person asking a question: What if we mixed the ash differently? What if the floor could be warm? What if the roof could open like a sail? The Romans were not superheroes; they were curious, careful, stubborn problem-solvers who tested things, failed, fixed them, and wrote down what worked. That is called engineering, and it is a superpower anyone can learn, including you.

Scientists are still learning from Rome, copying its concrete and marveling at its mathematics. And somewhere beneath its streets, undiscovered treasures are still waiting in the dark for the curious people of the future. Maybe one of them is you. Until then, toss an imaginary coin over your shoulder. Rome will be waiting. It is, after all, eternal.