The city of Tanis is relatively unknown among Egypt's wealth of historical sites, though it yielded one of the greatest archeological troves ever found. Once the capital of all Egypt, Tanis's royal tombs have yielded artifacts on par with the treasures of Tutankhamun.
Tanis was known by many names. Ancient Egyptians called it Djanet, and the Old Testament refers to the site as Zoan. Today it's called Sân el-Hagar.
The site, in the Nile Delta northeast of Cairo, was capital of the 21st and 22nd dynasties, during the reign of the Tanite kings in Egypt's Third Intermediate period.
The city's advantageous location enabled it to become a wealthy commercial center long before the rise of Alexandria. But political fortunes shifted, and so did the river's waters—and in recent centuries the Tanis site had became a silted plain with some hill-like mounds thought to be of little interest.
It was known that the ancient city was hidden somewhere in the area, but not where.
"People kept trying to identify different places with it," said Salima Ikram, a professor of Egyptology at American University in Cairo and a National Geographic Society grantee.
Egypt's "intermediate periods" were times of weak central government when power was divided and sometimes passed out of Egyptian hands. During this time the rulers of Tanis were of Libyan decent, not scions of traditional Egyptian families. That distinction may have contributed to the city's disappearance in later years.
"It's not like the Valley of the Kings, where everyone knew they'd been burying [pharaohs] for ten generations or so," said David Silverman, an Egyptologist at the University of Pennsylvania. (National Geographic)