New Research Says High Nile Water Levels Helped Build Giza Pyramids

The three main pyramids at Giza, Egypt, together with subsidiary pyramids and the remains of other structures at the Giza pyramid complex (photo via Wikimedia Commons)

Perhaps one of the most striking aspects of the pyramids at Giza — a massive monument complex built some 4,500 years ago, and one of the seven wonders of the ancient world — is the way they rise from the surrounding landscape of barren desert. The logistics of building such an edifice would be staggering under any circumstances, but moving the five million blocks of limestone overland using ancient technologies truly beggars belief. A recent research paper proposes a different vision of how the pyramids came to be built — one that hypothesizes a branch of the Nile that flowed adjacent to the site, making the transfer of materials a less daunting proposition.

This is not the first theory to posit a disappeared branch of the Nile, but the paper, published in late August in the peer-reviewed journal Proceedings of the National Academy of Sciences, supports this idea by analyzing core samples containing pollen. Five samples were taken from the Giza floodplain in 2019 to measure pollen levels over ancient times, thereby creating an “8,000-year fluvial history” of the region.

“It is now accepted that ancient Egyptian engineers exploited a former channel of the Nile to transport building materials and provisions to the Giza plateau,” reads the study’s overview. “However, there is a paucity of environmental evidence regarding when, where, and how these ancient landscapes evolved.”

Pyramids at Giza, Egypt are featured in this image photographed by an Expedition 32 crew member on the International Space Station. Core samples taken from the surrounding floodplain indicate that a lost branch of the Nile once flowed through this region. (image via Wikimedia Commons)

The study imagines the Nile at around 40% of its Holocene maximum. Based on pollen levels present in the core samples, the research proposes that the so-called “Khufu branch” of the Nile remained at a high-water level during the reigns of Khufu, Khafre, and Menkaure — the pharaohs for whom the pyramids at Giza serve as burial sites.

“It was a natural canal in the time of the fourth dynasty [when the pyramids were built],” study lead author Hader Sheisha, a physical geographer at Aix-Marseille University in France, told Live Science. “It would be very difficult if not impossible to build the pyramids without the Khufu branch and without it having a good level, which provides enough accommodation space for the boats carrying such heavy blocks of stone.”

These findings also impact our understanding of climate change throughout a larger scale of human history.

“To edify the plateau’s pyramids, tombs, and temples, it now seems that ancient Egyptian engineers took advantage of the Nile and its annual floods, using an ingenious system of canals and basins that formed a port complex at the foot of the Giza plateau,” according to the research.

While the pyramids will always retain an awe-striking air of mystery, science has managed to pierce the veil and offer a peek into the construction logistics and environmental conditions of one of human history’s greatest building projects.