How Were The Pyramids Built? Scientists Discover How Ancient Egyptians Moved Huge Stones

Camels and horses stand tied to a fence below the Great Pyramid of Giza on October 21, 2013 in Cairo, Egypt. Ed Giles/Getty Images

Constructed around 4,500 years ago, the Great Pyramid of Giza is one of the Seven Wonders of the Ancient World and the only one that remains largely intact. For centuries, there has been considerable debate about how exactly the ancient Egyptians built the structure with researchers proposing several different theories.

Now, a team from the French Institute for Oriental Archaeology in Cairo and the University of Liverpool, England, has uncovered evidence that casts new light on the mysterious construction process of the pyramid—which was built as a tomb for the Pharaoh Khufu (2609 BC-2584 BC).

According to a statement from the Egyptian Ministry of Antiquities, the archaeologists found the remains of a unique system for transporting and removing stone blocks from an alabaster quarry, called Hatnub, in the Eastern Desert..

Although, the Great Pyramid is mostly made from limestone, the Egyptians commonly used alabaster for some features, such flooring, as well as statues, coffins, tiles, vases and other objects.

The system that the archaeologists discovered to remove the alabaster was composed of a central ramp, surrounded by two staircases which contained several post holes.

"Using a sled which carried a stone block and was attached with ropes to these wooden posts, ancient Egyptians were able to pull up the alabaster blocks out of the quarry on very steep slopes of 20 percent or more," Yannis Gourdon, one of the directors of the archaeological mission, told LiveScience.

The ropes attached to the sled make it easier to pull the sled up the ramp, according to the researchers, who say this is the first time that such a system has been discovered in an ancient Egyptian quarry. The findings could provide insights into the enduring mystery of how the massive limestone blocks, which make up the majority of the pyramid, were hauled up its sides.

"This kind of system has never been discovered anywhere else," Gourdon said. "The study of the tool marks and the presence of two inscriptions led us to the conclusion that this system dates back at least to Khufu's reign, the builder of the Great Pyramid in Giza."

"That means that during the time of Khufu, ancient Egyptians knew how to move huge blocks of stone using very steep slopes," he added. "Therefore, they could have used it for the construction [of] his pyramid," Gourdon said.

The latest findings support many accepted construction hypotheses which suggest the pyramid was built by moving huge stones from a quarry which were dragged and lifted into place. However, there is much disagreement over what exact methods were used to achieve this.

There has also been much debate over the kind of the workforce used and its size. The ancient Greeks thought that the Great Pyramid was built using slave labor with construction involving around 100,000 men. But by the late 20th century, archaeologists found evidence that a more limited workforce composed of as few as 20,000 skilled workers may have been sufficient for the task.

Originally standing at around 481 feet high, the pyramid was the tallest building in the world for more than 3,800 years (although erosion and the absence of its capstone has now reduced this figure to around 455 feet).

It was completed around 2560 BC during Khufu's reign, with most Egyptologists estimating that the construction took between around 10 and 20 years. The monument is part of the larger Giza pyramid complex, which contains two smaller pyramids—built for the Pharaohs Khafre and Menkaure—as well as several other temples and tombs.