Two possible ancient dams near the Red Pyramid on the Dahshur Plateau, Egypt

This study presents, for the first time, evidence of two ancient, giant dams built across Wadi Dahshur, Egypt, along with a water diversion channel west of the Red Pyramid (ca. 4.55–4.53 ka BP). Satellite imagery and watershed mapping show that the two long structures, previously interpreted as stone transport ramps, exhibit the technical signature of dams, each extending 600–700 m and anchored to the valley flanks. The eastern structure likely served as the main water-retention dam, whereas the western structure, equipped with a duckbill weir, may have acted as a check dam, trapping sediment and regulating flow into the diversion channel. Hydrological analyses suggest that Wadi Dahshur connects to western tributaries of Wadi Taflah, potentially granting access to a ~100 km² catchment, possibly ~400 km². The dam’s proximity to the Red Pyramid and the nearby diversion canal point to a possible use of water resources during its construction.