10 years in the making, experts have recreated Rome. According to a BBC report, users enter the city at the time of Constantine and see inside buildings.
The simulation takes place in AD320, which is said to be the city's peak, when it had grown to a million inhabitants.
"We can take people under the Colosseum and show them how the elevators worked to bring the animals up from underground chambers for the animal hunts they held," said Bernard Frischer, the project's leader who heads Virginia's Institute for Advanced Technology in the Humanities.
The simulation reconstructs the interior of about 30 buildings - including the Senate, the Colosseum and the basilica built by the emperor Maxentius - complete with frescoes and decorations.
The project brought together experts from the University of Virginia and the Los Angeles branch of the University of California, as well research institutes in Italy, Germany and the UK.
Bernard Frischer, of Virginia's Institute for Advanced Technology in the Humanities calls it a "virtual time machine."