Watch a report from ITV Anglia's Rebecca Haworth
A complete digital copy of Peterborough cathedral, accurate to 3mm, is being created in what is believed to be a European first.
A team of architects have been scanning the entire building with lasers, part of which involves abseiling down the building's famous west front.
The scan is intended to be used for architectural and educational purposes and the level of detail involved is groundbreaking, according to one of the architects involved.
Graham Sykes, of Architectural and Heritage Scanning, the company behind the project, said: "We think there's been no other English Cathedral if not European Cathedral that's been scanned and detailed to this high level.
"We've not only carried out a survey, but we've essentially created a digital twin of the building.
"So we have approximately 1.6 terabytes of data so far, 16 billion data points, and we'll have in the region of 30,000 images.
"What we'll have by the end of it is the most documented building in the country, if not in Europe."
The digital version is expected to be used by school groups, who will be able to see parts of the cathedral they would not usually be able to access.