"[U]ntil now, they have never been fully documented, their vast scale only recorded with handmade maps.
That is now changing, following a three-year project to create the first fully comprehensive three-dimensional image using laser scanners.
A team of 10 Austrian and Italian archaeologists, architects and computer scientists have started with the largest catacomb, Saint Domitilla, just outside the Italian capital.
The tunnels, caves, galleries and burial chambers of Saint Domitilla stretch for about 15km (9 miles) over a number of levels."
"...Yet, because of concerns about safety, only about 500m (1,640ft) are accessible to the public today.
The new, moving, images of this entire underground system will change all that and open up this beautiful subterranean world in a way that it has never been seen before."