Have you ever stood in front of historic ruins—the Parthenon, say, or one of Britain’s many ancient castles—and closed your eyes, imagining what the scene before you would have looked like centuries ago?

Thanks to virtual reality, seeing ruins as they looked in their heyday is becoming possible. It may even be a game changer for the ways we visit ancient cities like Jerusalem or Paris.

When I catch up with Australian archaeologist Simon Young, he’s in Rome.

“It’s low season at the moment in Italy, but there are still hundreds and thousands of people wandering in the streets and looking at ruins,” he says.

Young would like to show those people what Rome looked like nearly 2,000 years ago by fitting them with virtual reality headsets. His company, Lithodomos VR, creates immersive virtual recreations of iconic ruins. The recreations can be used on site with a smartphone headset, or from home or school using a commercial VR system like Oculus Rift.

“It’s 360-degree 3D virtual reality,” Young says. “It really helps you to place yourself back in time.”

Today, Rome’s Temple of Venus and Rome lies split in half, most of its columns gone, ravaged by centuries of fire, earthquakes and pillaging. But put on a virtual reality headset with Lithodomos’ app, and suddenly it’s a June afternoon in the 1st century AD. The temple before you is whole again, its vanished columns standing tall, its façade all shining white marble, the intricate relief sculptures of its pediment cast in shadow by the summer sun.

The app maps your physical location onto the temple, allowing you to look around from various angles. It might be raining outside, or nighttime. But in the VR world, the sky is a hazy blue, the perimeter of the temple lined with trees.

In addition to the Temple of Venus and Rome, Lithodomos has a recreation of the Arènes de Lutèce, a Roman amphitheater and stage from the beginning of the 2nd century AD, now just fragments tucked away behind apartment buildings in Paris’s Latin Quarter. It’s also recreated the Odeon of Agrippa, a concert hall in the center of the Athenian agora, and parts of ancient Jerusalem. The scenes are available on two Lithodomos apps released in December and January. Young plans to work on scenes from Delphi, Spain and the UK in the near future.

Young sees his software being used by tour groups who would provide their guests with headsets, or by individuals using cheap, portable viewers like Google Cardboard. He also hopes to partner with museums and universities to create other historical VR experiences, such as allowing museum-goers to view artifacts up close and in 360 degrees.

Lithodomos is not the only company working on historical VR. Singapore-based Hiverlab has ambitions to digitize heritage sites across the world. So far they’ve created a VR tour of a medieval Armenian church in Cypress, which lets users wander the structure as it is today, as well see what it might have looked like centuries ago. The free Timelooper app lets viewers experience various historical moments—George Washington’s second inaugural address, the construction of the Empire State Building, the Great Fire of London.

In the past several months, Young says, several tour operators in Rome have begun offering VR-enhanced tours. The day before, he’d been to the Domus Aurea, the “Golden House” built by Nero in the 1st century AD. The site’s superintendent had installed an Oculus Rift experience, and visitors were busy checking it out.

“One woman swore, she was so amazed by the experience,” Young says.

But as an archeologist, Young worries that some companies offering ancient world VR experiences aren’t serious enough about accuracy.

“Some game developer in Silicon Valley who has no idea thinks, ‘oh, a column would look great there,’” he says. “The real danger is that, because VR is such a powerful medium, if someone visits the Colosseum, they walk away with the idea that this is what it was like.”