Researchers discovered a hidden tunnel inside the Great Pyramid of Giza, as Egypt’s tourism minister, Ahmed Issa, announced on March 2.

The nine-meter-long passageway is located near the main entrance of the Pyramid of Khufu, behind the chevron zone on the north side.

Researchers were with Scan Pyramid, an organization that uses modern technology to observe the inner structure of pyramids.

Since 2015, they have been using Radiographic muons, infrared thermography, and 3D reconstruction to try to understand what is within these pyramids.

While researchers are still not certain of the tunnel’s function, Mostafa Waziri, head of Egypt’s Supreme Council of Antiquities, told reporters at the site that they suspect that due to its gabled ceiling, it is meant to alleviate the structural weight.

“But a big question mark hangs over whether this corridor was created to relieve the weight on the [main] entrance or lighten the load on a space yet to be discovered,” he stated, as obtained by ABC.

There will be more scanning done to the pyramid that will hopefully clear up some of the mystery surrounding the structure.

The construction process of the Great Pyramids of Giza has always been mysterious to archaeologists. The pyramids consist of over a couple of million stone blocks, which each range from 2.5 to 16 tons in weight. Some of the blocks were found to have originated some 500 miles away from Giza. Scientists have not found a satisfying answer to how ancient Egyptians were able to construct and move all this weight without the tools we have today and even without simple tools like the wheel.

Hopefully, learning more about the internal structure will aid researchers understand how the pyramids were built.

Built around 4,500 years ago, the pyramids are the last remaining wonder of the ancient world.

The discovery of the hidden tunnel comes six years after one of the first major findings using scanning technology in 2017. During the scanning process, they discovered a large cavity by using cosmic-ray muon radiography.