From Live Science:
Images captured from space pinpoint telltale signs of previous habitation in the swatch of land 200 miles south of Cairo, which digging recently confirmed as an ancient settlement dating from about 400 A.D.
The find is part of a larger project aiming to map as much of ancient Egypt's archaeological sites, or "tells," as possible before they are destroyed or covered by modern development.
"It is the biggest site discovered so far," said project leader Sarah Parcak of the University of Alabama at Birmingham. "Based on the coins and pottery we found, it appears to be a massive regional center that traded with Greece, Turkey and Libya."