The pyramid — also known as Khufu’s Pyramid — was built on the Giza plateau on the outskirts of Cairo by pharaoh Khufu, a 4th Dynasty pharaoh who reigned from 2509 to 2483 B.C.
But parts of the history and structure of the 4,500-year-old pyramid have remained shrouded in mystery.
The latest discovery is part of the international “ScanPyramids” project launched in Oct. 2015 by Egypt’s Ministry of Antiquities, which seeks to peer inside the massive structures without using invasive drilling methods.
Instead, scientists used “non-invasive and non-destructive surveying techniques” called muons radiography, developed in Japan by Nagoya University and the High Energy Accelerator Research Organization.
Among several thermal anomalies discovered in Nov. 2015, significant anomalies were detected the following year on the Northern Face of the Great Pyramid, where four upside down v-shaped chevrons were seen overhanging the descending corridor.
The technique tracks cosmic ray muon particles that bombard Earth at close to the speed of light and penetrate solid objects more effectively than X-rays, allowing scientists to accurately visualize the presence of unknown structures within.
In 2017, scientists using the same technique discovered what they said was the first major inner structure found in the pyramid since the 19th century, when they found a “void” or “cavity” called the Grand Gallery, one of a series of passageways and chambers.
In addition to the Grand Gallery, archaeologists previously found the king’s chamber, roughly in the center of the pyramid, and a smaller queen’s chamber nearby.
Charlene Gubash, Reuters and Molly Hunter contributed.