A team of Italian archaeologists, architects and technicians is working on the ancient Egyptian tombs of Sakkara to find ways of preventing the presence of visitors from damaging the tombs' decorations.
Visitors' breath and the brushing of clothing against the walls are considered the greatest threats to the wall paintings and bas-reliefs that illustrate aspects of life in ancient Egypt, including fishing, the slaughtering of animals and people at prayer.
Sakkara, famous for its "step" pyramids, is set in an oasis about 20km south of Cairo. It was the necropolis of Memphis, capital of lower Egypt and capital of united Egypt ( c .3100-2250BC). The tombs at Luxor housed the remains of the pharaohs of Thebes, capital of upper Egypt.
The team is headed by Edda Bresciani, professor of archaeology at Pisa University, who was also involved in the excavations of the buried city of Medinet Madi.
The team coordinator is architect Antonio Giammarusti, who worked on moving the temple of File when the Aswan Dam was built.
"We want to prepare a programme of alternate opening and closing of the various tombs, so as to give each tomb a chance to eliminate the pollution produced by visitors and thus minimise the damage," Mr Giammarusti said.
A similar system has been adopted at the larger and better-known pyramids of Giza, just outside Cairo. The Egyptian ministry of tourism has supplied the Italians with statistics on tourism so that a timetable for opening and closing tombs can be prepared in the context of the seasonal ebb and flow of visitors.
At Sakkara, there are about 600 tombs around the great pyramid of Zoser, which is believed to be the oldest of the stone pyramids. But fewer than a dozen are open to visitors.
The Italians are using satellite photographs and GPS bearings to make a detailed map of the entire necropolis.
The team is also collecting documents regarding discoveries and excavations over the past 200 years. Mr Giammarusti said: "We have found a series of rare photographs and very old reports. In many cases, these are the only clues to what some of the old monuments were like."
Emanuele Brienza, the team's computer specialist, added: "We are producing an updated archaeological map of Sakkara, which gives us traces of monuments that no longer exist."
The project is backed by €632,000 (£420,000) from the Italian government.