Computer experts have unveiled a digital reproduction of ancient Rome as it appeared at the peak of its power in AD 320.
Visitors to virtual Rome will be able to crawl through the bowels of the Colosseum, filled with lion cages and primitive elevators, and fly up for a detailed look at bas-reliefs and inscriptions atop triumphal arches.
"This is the first step in the creation of a virtual time machine, which our children and grandchildren will use to study the history of Rome and many other great cities around the world," said Bernard Frischer of the University of Virginia, who led the project.
The $2 million simulation will be used by scientists to run experiments - such as determining the crowd capacity of ancient buildings - and as a scholarly journal that will be updated at each new discovery of one of Rome's marvels.
Mr Frischer also said students and tourists can also use the programme to learn about ancient Rome.
The simulation reconstructs some 7,000 buildings at the time of emperor Constantine, when Rome was a vibrant and cosmopolitan city of about one million people.
Guided by laser scans of modern-day Rome and advice from archaeologists, experts have rebuilt almost the entire city within its original 13-mile-long wall using the same computer programmes architects use to plan new constructions, he said.
It even includes the interiors of about 30 buildings - among them the Senate, the Colosseum and the basilica built by the emperor Maxentius - complete with frescoes and decorations.
The simulation shows statues and monuments as they would appear without the dark smudges left by pollution. The computer experts also were able to accurately recreate buildings that are now almost in ruins, such as the temple dedicated to the goddesses Venus and Roma and the Meta Sudans, a fountain that stood near the Colosseum, Mr Frischer said.
The programme was created over 10 years by an international team of archaeologists, architects and computer specialists.
AP