In the fourth century AD, Rome was a sprawling megacity feeling secure about its prominence as the undisputed capital of the world. The recently constructed Aurelian Walls enclosed the city in a fortified embrace, strong enough to fend off any pesky barbarian invaders, the city fathers assured. Inside the walls was a city spanning 35 square kilometres, home to more than a million people.

Of course, repeated attacks that began less than a century later would eventually topple the city. Waves of thugs would pillage and loot, leaving the city in a schizophrenic state, much of it still evident today. A number of scattered ruins stand incongruously beside modern apartment buildings and shops. And, not far from my apartment, the massive Aurelian Wall still looms, a reminder of Rome’s ancient splendour, and its vulnerability.

Academics and researchers have been studying Rome for centuries, trying to piece together what it must have been like inside those ancient walls. A city of that size would require an unprecedented level of urban planning to move people, livestock and traffic around in an orderly fashion. It would also require some level of policing, not to mention local ordinances to designate the rules of commerce, taxation and sanitation.

A good deal about life in ancient Rome has been pieced together, but countless gaps remain.

A group of international researchers hope to fill in some of those voids with a recently unveiled full-sized, three-dimensional map of Rome. The map is a magnificently precise rendering of Rome, circa AD320. It contains details of the 7,000 buildings – in many cases, down to the shades of the tiles – contained within the walls of ancient Rome at the time, allowing the user to fly over much of the ancient city, gliding through the chariot lanes of the Circus Maximus and climb the steps of an intact Colosseum.

The virtual map, called Rome Reborn, is the culmination of a ten-year-old project spearheaded by Bernard Frischer, director of The Institute for Advanced Technology in the Humanties at the University of Virginia, and Diane Favro, director of Experiential Technologies Center in UCLA, plus a team of 3D modelling and scanning experts from University of Virginia and the Politecnico di Milano.

Scanning every street corner, archway and column may have been the easy part. The next ambition is to bring Ancient Rome to modern-day netizens. At 800 megabytes, the map is too dense to host on the web for people to take a stroll through. As Frischer explains, “once you move through this world, all the polygons have to be recalculated at least thirty times per second to give the illusion of fluid motion. The computer has to make computations of hundreds of thousands of polygons, and add to that half a million simultaneous users.”

The bandwidth required would be enormous – supercomputer enormous, he says. That is unless you could develop a nimble, Second Life-style version that would cheat on the polygon crunching, opting to consider just the crucial bits – no more than a few hundred million polygons, say – that add the depth and perspective to a scene while leaving the remaining hundred million or so unchanged. “Like a big mash-up,” Frischer says with increasing animation.

Frischer has been in talks with Linden Labs and other online “multiverse” pioneers to bring Rome Reborn to the masses. (At the moment, the Rome Reborn map is more a guided tour than a virtual world where you can freely walk around.) Still, it could be some time before we see ancient Roman avatars setting up shop to repair chariot wheels or peddling designer terracotta jugs to fellow digitised Romans.

But Frischer is convinced that virtual worlds are the future for studying ancient civilisations. Digging in the dirt at archaeological sites is still essential to fill in details about the aesthetics of antiquity. But to truly understand a civilisation, scholars need to immerse themselves in that world, he says, by transacting in the ancient currency, abiding by the rules of engagement of the day. From such transactions come a deeper understanding of the way ancient peoples may have interacted, how they settled disputes, how riches were amassed and dynasties formed.

Frischer envisages roles for everybody in a digital world of ancient Rome from Classics professors to teenage gamers to virtual tourists.

First, you would have the scholars, the true experts of ancient Rome. They could apply the laws of the time to the virtual world, helping, say, to set a starting value for the currency, a type of digital “denarius,” the silver pieces favoured for most transactions in ancient Rome. Those with lesser qualifications could get their start as citizens, or, possibly lower, as slaves who need to work their way up to citizenship. Finally, you have tourists. Tourists would pay a small fee to watch the digital throngs interacting on market day or taking in some gladiator games at the Colosseum.

Of course, there is a monetary aspect to this. Experts could use their knowledge to start a business in virtual Rome, Frischer imagines, earning cash while simultaneously conducting research. “They could monetise their knowledge,” he says. “You could see the classics becoming a hot field of research again.”

For those of you considering entering ancient Rome as a barbarian avatar, I have some bad news. This is Rome in AD320, a time of sustained domestic peace and prosperity. If you want to sack, pillage and commit other unspeakable acts, you’ll have to wait another 90 years, until AD410 comes around.