Updated

Kathy Choi touches a kiosk screen, then looks up at a larger wall screen to see digitally created yellowish-brown mounds snaking through bright green grassland dotted with brilliant blue rivers and lakes.

The ancient earthworks in the Ohio River Valley now are grass- and tree-covered mounds and walls diminished by development, floods and agriculture. But she's seeing them as they might have looked 2,000 years ago, by way of a computerized fly-over. "It makes it all seem more real," said Choi, 59, of Covington, Ky., maneuvering her way through the Cincinnati Museum Center's interactive video tour of Fort Ancient and other earthworks.

Archaeologists and historians agree. Museums, educators and others are increasingly using video, animation, graphics and other technology to depict historical sites beyond what text, maps and drawings offer.

On a virtual tour of an 18th-century American Indian village in North Dakota, visitors can enter an earthen lodge and hear sound effects as the animated figure of a woman scrapes a deer hide. The Archaeology Technologies Laboratory at North Dakota State University used 3-D computer visualizations to re-create the On-A-Slant village of the Mandan, a tribe that inhabited the Plains area.

The Colonial Williamsburg Foundation is creating a virtual 3-D model of a recently excavated theater in Williamsburg, the restored 18th-century capital of Virginia. The foundation also plans to add animation to the theater project and eventually create a virtual tour of the entire town, said Lisa Fischer, manager of the foundation's digital history center.

An exhibition at the Museum of Fine Arts, Boston, used computerized 3-D animation to re-create a temple and a palace built by Egyptian Pharaoh Akhenaten and Queen Nefertiti. The museum plans a virtual heritage exhibition next year on the Assyrian empire.

Phil Getchell, the museum's director of new media, said museum officials are looking for other new ways to use virtual reality technology, and he sees museums increasingly turning to virtual heritage.

"It really seems to have taken off over the past two or three years, especially as it has become more affordable," Getchell said.

Virtual heritage exhibits and projects — considered novel a decade ago — have become popular in Europe and parts of Asia, where there has been more national funding. Virtual heritage projects are found in several countries including Italy, Germany and Japan.

They are gaining momentum in the United States as computer speed and technology improve and costs drop. Equipment costing more than $1 million a few years ago can now be purchased for tens of thousands of dollars less.

"Depending on the project, you can still spend a lot generating the content itself, but the equipment and technology is easier to use and more affordable," said Donald Sanders, president of Learning Sites Inc., a company that designs and develops interactive 3-D models of sites, including those of a palace at Nimrud in Iraq.

At the Hood Museum of Art at Dartmouth College in Hanover, N.H., visitors can view actual stone reliefs from the palace of a ninth century Assyrian king, Ashurnasirpal II, at Nimrud. A computer animated fly-through of digitally reconstructed palace rooms shows the reliefs in their original locations. Visitors also can navigate their way through a virtual tour of a 3-D model of the palace.

Virtual heritage also is seen as a way to digitally preserve and document sites threatened by the environment, pollution or — like the palace at Nimrud — by warfare and looting and a means of improving people's understanding of the past.

"It creates a vivid image that can persist in the public imagination and provide more insight and appreciation of lost architecture and cultures," said John Hancock, a University of Cincinnati architecture professor and director of "Earthworks: Virtual Explorations of the Ancient Ohio Valley."

The interactive video tour has traveled to sites in Ohio and Kentucky, and discussions are under way to take it to museums in Indiana, Minnesota, Oklahoma and Connecticut. Parts of the traveling exhibit are permanently displayed at such sites as the Cincinnati museum and the Field Museum in Chicago.

The Adena, Hopewell and Fort Ancient American Indian cultures that flourished 800 to 2,400 years ago built the earthworks, which include mounds and enclosures of varying sizes, often in geometric or animal shapes. Some were used for ceremonial and social activities.

The 18,000 feet of ancient earthen walls at Fort Ancient north of Cincinnati contain enough soil to fill 200 miles of dump trucks carrying 15 to 20 tons each and laid end-to-end.

In trying to find the best way to re-create the earthen architecture, Hancock's team first thought the animation camera had to move viewers as if they were walking on the ground since most virtual heritage projects involve more standard types of architecture such as buildings where the camera moves alongside and even into sites. But they decided to move the camera up, providing a bird's-eye view to give viewers a better idea of the scope of the earthworks when they were intact.

Reconstructions in movies such as "Gladiator" have pressured university research and media labs to make their projects look more real, but virtual heritage reconstructions aren't intended to compete with Hollywood or replace site visits, Hancock said.

"You see that these are computer representations. But if done well enough, people can get just the right amount of reality to spark their imagination," he said.

Advocates have raised concerns about how to verify data used to create reconstructions and make sure the public understands that no reconstruction can be exact.

Jeffrey Clark, director of the North Dakota State laboratory that created the On-A-Slant project, said colleagues at a Berlin conference he recently attended discussed how to make sure the public understands the limits of virtual reconstruction.

"Archaeologists realize that any reconstruction — physical or virtual — is only conjecture, but the casual museum visitor may attach a validity to it that isn't there," he said.

Some Italian colleagues at the Berlin conference proposed a "sliding scale of certainty" that would rank the level of confidence archaeologists have in a particular reconstruction. No formal guidelines have yet been adopted.

Despite potential drawbacks, virtual heritage is moving forward, researching ways of connecting to senses other than vision and hearing and even the possible use of holograms.

"History didn't happen in 2-D," Sanders said. "It happened in 3-D with people interacting with each other, and that's why this field will grow as the benefits become more understandable."