A new report published in the journal PLOS ONE explains why a team of experts concluded that the ancient Egyptians were probably the first hydraulic engineers to use modern technology to build the giant pyramids in the middle of the desert.

The study focused on Egypt's oldest pyramid: the tomb of pharaoh Djoser, known as the Pyramid of Djoser.

The Pyramid of Djoser was built around 2680 BC (27th century BC). At that time, hunter-gatherer tribes had just begun building Stonehenge in England, and the last remaining woolly mammoth population still roamed freely on Siberia's Wrangel Island.

At the time of its completion, Djoser's pyramid was the tallest structure of its time, standing at over 62 m (200 ft) high. The legendary pyramid still stands today in Saqqara, about 15 km (9 miles) southwest of the Giza pyramid complex.

However, how this pyramid was built remains a mystery, mainly questions related to how to move the 300 kg stone blocks up high.

"Many detailed reports have discussed the pyramid-building processes and provided clear explanations, but all have focused on the more recent, smaller, and well-documented pyramids of the Middle and New Kingdoms of Egypt (1980 to 1075 BC)," said team leader Dr. Xavier Landreau, Director General of Paleotechnic, a private institute in Paris that studies ancient technologies.

How did the ancients do it?

Using a new approach, Dr. Landreau's team was the first to propose a hydraulic system installed in the heart of the pyramid that could have transported huge blocks of stone.

Djoser's Pyramid consists of about 2.6 million limestone blocks, each weighing about 300 kg. The pyramid has 6 floors, is 62.5 m high and has a base width of 121 m.

Over 150 years, the ancient Egyptians built six more pyramids, moving a total of more than 20 million tons of stone. Dr. Landreau's team calculated that every hour over those years, nearly 50 tons of stone were cut, moved, and placed in place.

Researchers believe the ancients used a controlled dam to hold water to operate a hydraulic device that moved stones through the pyramid. The device worked like a hydraulic lift system.