Abu — the name means both elephant and ivory — was settled from very early in Egyptian history and functioned as a fortress, a trading post and a customs point.
The island was home to a temple of Khnum, the ram-headed god who was believed to control the flood from caverns beneath the cataract.
It also produced one of the most unusual documentary finds in Egypt: papyri from a Jewish military colony stationed here in the fifth century BC, whose letters record their community life on the frontier.
The papyri deserve their fame. The garrison's soldiers lived here with their families, kept their records in Aramaic, and maintained a temple to their god within sight of the temple of Khnum. Their letters — marriage contracts, property disputes, an appeal for help rebuilding their temple — are among the most vivid ordinary documents to survive from the ancient world.
Three thousand years of rebuilding on the same ground is why the southern ruins read as layers rather than as one monument. The reconstructed Temple of Satet marks a shrine site that goes back to Egypt's earliest dynasties, rebuilt again and again on the same spot.