The unfinished Obelisk Quarry in Aswan, Egypt, has a canal that may have connected to the Nile and allowed the large stone monuments to float to their permanent locations, according to an international team of researchers. This canal, however, may be allowing salts from ground water to seep into what has been the best preserved example of obelisk quarrying in Egypt.
"Working deposits and surfaces exposed during excavation are being damaged by accumulation of salts," the researchers said at the Second International Conference on Geology of the Tethyr at the Cairo University. "These unique artifacts document quarry methods and should be preserved."
The granite quarry, located on the east bank of the Nile in the center of Aswan City, contains a very large unfinished obelisk that was not completed because of latent cracks. While the cracks were bad for the ancient Egyptian stone carvers, the unfinished monument provides the opportunity for archaeologists to understand how people worked hard stone quarries.
Pretty neat. I went there once in 1991.