The pyramids of Giza, erected some 4,500 years ago, represent one of the greatest feats in the history of engineering, and their construction has long raised a mix of interest, fascination and disbelief. Today, it is widely accepted that ancient Egyptians exploited an ancient branch of the Nile that flowed near the Giza plateau to transport the materials they needed to build the three structures. But the evolution of that landscape that facilitated the construction of one of the wonders of the ancient world has largely remained a mystery.

To help fill this gap, a group of scientists has reconstructed, based on new sediment analysis from the site, 8,000 years of fluvial history of the Nile. They have been able to show that the river’s now-vanished branch, which they named after Pharaoh Khufu, and its water levels at the time the pyramids were built were key to their construction.

“Our 8,000-year reconstruction of Khufu-branch levels improves our understanding of fluvial landscapes at the time of the construction of the Giza pyramids complex, and demonstrates that Old Kingdom engineers harnessed the fluvial environment — the Nile and its annual flood — to exploit the plateau overlooking the floodplain for monumental construction,” said Hader Sheisha, environmental geographer at Aix-Marseille University in France and one of the study’s lead authors.

The study led by Sheisha notes that today there is broad consensus that ancient Egyptians took advantage of the Khufu branch and the Nile’s annual floods to develop a system of canals, basins and a port at the foot of the Giza plateau. And it was largely thanks to this water transport infrastructure, about which relatively little is still known, that they were able to build colossal structures such as the pyramids of Menkaure, Khafre and Khufu.