When I explain that I've written a book about ancient Rome, people always ask about the research. Did I scour the remotest ruins of Italy, like some bespectacled Harrison Ford? Or did I visit the Cinecitt film studios, where they've been shooting Rome, the raunchy new HBO series that promises to be Deadwood with togas? Well, yes. But to capture the fabric of ancient life, I didn't really have to leave home.

The ideal place to be writing about imperial Rome, from an imaginative point of view, is right here in New York.

In fact, every time I wake up in my cramped East Village apartment, all I have to do is squint and I might as well be back in the Subura, Rome's feistiest neighborhood in the days of the Caesars. The Subura (nobody knows where the name comes from) was the original gritty downtown: Located conveniently close to the Forum, it was jammed full of tenement houses, each six stories high, called insulae or "islands," and broken into rental apartments that were touchingly familiar—notorious, one historian says, for "the fragility of their construction, the scantiness of their furniture, insufficient light and heat, and the absence of sanitation." In those days, harassed Roman tenants would climb 200 steps to their top-floor garrets, whose walls were so thin they could overhear the most intimate sounds of their neighbors (and this before stereos). They battled rapacious landlords, who ignored the most basic building repairs: "The agents propped up a tottering wall," notes one historian, "or painted a huge (ceiling) rift over, and assured the occupants that they could sleep at their ease, all the time that their home was crumbling over their heads." Adding insult to injury, they paid extortionate prices for the privilege:

"Ever-rising rent was a subject of eternal lamentation in Roman literature," notes the French historian Jér Carcopino of the brutal real estate market.

We know all this because back in the first and second centuries AD the Subura was full of impoverished Roman writers like Juvenal and Martial, bitching about their tiny apartments and the indignities of their impecunious lives—and surprise, surprise, it doesn't take a huge historical leap to get inside their heads.

Just listening to my beloved 10th Street cacophony every morning puts me at one with the ancients: "Insomnia is the main cause of death in Rome," ranted Juvenal. "Show me the apartment that lets you sleep!" Of course, instead of sirens and car alarms, the Romans were driven mad by the shrieks of street vendors and bells from pagan rituals. The night traffic was deafening: Axle grease was rarely used in ancient times, so the high-pitched squeal of wagon wheels grinding through the narrow streets was as piercing as the brakes on New York's garbage trucks.

Whenever I make my way downstairs to the rubbish-strewn sidewalk, I can gather more inspiration about ancient life: Strolling the Subura was once an assault on the senses, weaving through an obstacle course of filth and pushy crowds. ("One man digs an elbow into my side, another a hard pole," wrote Juvenal, "one bangs a beam, another a wine cask, against my skull.") There were serious dangers from above: Rome was a permanent construction site, and you had to look out for falling bricks as well as the fetid slops from chamber pots; whole buildings would regularly collapse, swallowing their unlucky tenants. Today, we New Yorkers still have to keep an eye out for falling scaffolding, pot plants, masonry, or air-conditioners—although even the Romans would have been appalled at the scale of the Henry Hudson Parkway collapse last May.

Squalid as it could be, the Subura lured aristocrats slumming on bar crawls and even became home to some of the bohemian Roman rich, whose palatial villas the author Pliny the Elder once compared to "the mad schemes of kings." As for me, I walk every day past the glittering new Astor Place Tower, boasting a price tag of up to $12 million an apartment. "Where has the purse of greed yawned wider?" asked Juvenal, wondering why the Romans had set up no altars to Mammon, the pagan god of wealth.