Visitors to the exhibit on antiquities at the new Getty Center in Los Angeles usually have the same response when they reach the computer-generated display near the end: They gasp. Then they gawk.
That's because the wall-high screen allows viewers to visit, virtually, the Second Century Forum of Trajan, the largest and most elaborate of the Roman Empire's public plazas.
For the first time, a three-dimensional computer model gives the viewer the feeling of walking through the two-story, marbled basilica, of gazing up from a forested courtyard at the hundreds of statues and friezes holding up cornices, of marvelling at the intricate sculpted relief on the 140-ft high Column of Trajan.
In short, the viewer can get a sense of how the monument looked to a Roman citizen 18 centuries ago.
Using technology dreamed up for flight simulators and Hollywood special effects, an alliance of computer wizards, architects, curators and historians is creating a new way to understand the monuments of earlier civilisations.
"It's like computerised time travel," says Mr James Packer, a Northwestern University classics professor whose 25 years of research on the Forum of Trajan became the basis for the computer model.
Trajan, who ruled Rome 150 years after Julius Caesar, set out to create the most magnificent public plaza of the Roman Empire, including a library, temple, two column-lined walkways and the famous column, which was topped with a statue of the emperor. It is believed to have stood for 700 years until most of it was destroyed in a 9th-century earthquake.
Eventually a Roman neighbourhood was built over the ruins. The forum was first excavated by Napoleon and later by Mussolini.
At the Getty, the "visit" to the Forum of Trajan (different from the Roman Forum) takes place on a large screen in a room filled with actual remains from the forum, including the torso of a Dacian, one of the peoples conquered by Trajan.
The Getty hopes to use the model for further study at its research institute, and might make the recorded tour accessible on the Internet.