BEIJING, July 25 (Xinhuanet) -- Scientists have found hidden underwater traces of a city that existed at Alexandria seven centuries before Alexander the Great swept through Egypt during his quest to conquer the known world.

    Alexandria was founded in Egypt on the shores of the Mediterranean in 332 B.C. to immortalize Alexander the Great. The city was famous throughout the known world for its library, once the largest in the world, as well as its lighthouse on the island of Pharos, one of the Seven Wonders of the Ancient World.

    Alexandria developed from a settlement known as Rhakotis, or Ra-Kedet, vaguely alluded to as a modest fishing village of little significance by some historians. Seven rod-shaped samples of dirt gathered from the seafloor of Alexandria's harbor reveal there may have been a flourishing urban center there as far back at 1000 B.C.

    Coastal geoarchaeologist Jean-Daniel Stanley, a coastal geoarchaelogist with the Smithsonian's National Museum of Natural History and his colleagues used vibrating hollow tubes to gently extract 3-inch-wide rods of sediment 6 to 18 feet long (2 to 5.5 meters) from up to 20 feet (6.5 meters) underwater.

    "Alexandria was built on top of an existing, and perhaps quite important, settlement, maybe one that was minimized in importance because we can't see it now," Stanley told LiveScience. "Nothing really concrete about Rhakotis has been discovered until now."

    High levels of lead that was likely used in construction, ceramic shards, building stones imported from elsewhere in Egypt and organic material likely coming from sewage were detected in the sediment samples. These all suggest the presence of a significant settlement long before Alexander the Great came. The results are detailed in the August issue of the journal GSA Today.

    Alexander probably chose this area for Alexandria because it had a bay to protect a harbor against fierce Mediterranean winter storms.

    "There are very few places in the Egyptian Mediterranean coast where the coastline is not smooth," Stanley said. "This would have been the best place to establish a harbor."

    (Agencies)