Builders of Egypt’s oldest known pyramid, the nearly 4,700-year-old Step Pyramid of Djoser at Saqqara, may have used waterpower to help construct this monumental structure. Ancient architects might have designed a hydraulic system to hoist stone blocks, used to assemble the six-tiered, roughly 62-meter-tall pyramid of King Djoser. This proposal, detailed by scientists in PLOS ONE, suggests that controlled water flows in and out of a large shaft inside the pyramid lifted and lowered a platform carrying building stones to higher levels. Xavier Landreau, from the Paris research institute Paleotec…