But Egyptian antiquities officials say they will now insist that archaeologists devote their attention instead to the Nile Delta.
Egypt is calling for a major salvage operation for the ancient monuments of the northern agricultural region known as the Nile Delta.
Antiquities officials say the archaeological treasures of what was Egypt's gateway to the Mediterranean and Africa are threatened by new building works and rising ground water levels.
The call is being made as archaeologists from around the world gather in Cairo for a key event in the study of ancient Egypt - the International Congress of Egyptologists.
The Congress is held every four years and opens on Tuesday beside the Pyramids.
Southern bias
Until now, most excavation work in Egypt has focused on the south of the country known as Upper Egypt.
It is there that some of the most famous treasures have been discovered, such as the tomb of Tutankhamen in Luxor and the Valley of the Kings and Queens.
But Egyptian antiquities officials say they will now insist that archaeologists devote their attention instead to the Nile Delta.
The head of Egypt's Supreme Council of Antiquities, Gaballah Ali Gaballah, says that important monuments believed to lie under the Delta are in great danger.
History may be lost
The problem is a combination of rising ground water and Egypt's relentlessly expanding population.
It is partly because of the ground water that archaeologists have been reluctant to dig in the Nile Delta.
Finds are easier to make in the sandy south of the country than in its lush fields.
But now new homes and schools are being constructed across this rich archaeological area and more land is coming under cultivation.
At the same time experts say the ground water is eating away at the monuments.
Egypt is now warning that unless urgent action is taken, layers of history will be lost forever, leaving future generations with a one-sided picture of the country's ancient past.