Archaeologists are investigating a large, angular space underground in an unexplored area of Egypt's most famous pyramids.
The Giza pyramid complex is the largest in the world, consisting of several ancient structures including the Great Pyramid, Pyramid of Khafre, Pyramid of Menkaure, and several smaller sites.
Using a technique called electrical resistivity tomography (ERT), scientists got a 3D image of the zone in question, and identified an L-shaped "anomaly" measuring at least 33 feet long.
The study revealed the structure "seems to have been filled with sand, which means it was backfilled after it was constructed".
A paper published on May 5 in the journal Archaeological Prospection said: "This anomaly extends to 3.5–10 m in depth and over a horizontal area of 10 m by 10 m."
Understanding the composition and dimensions of the anomaly is important for predicting whether it is man-made or just a naturally occurring phenomenon.
An Egyptologist said the passage stands out from other studies because there is no evidence of a standing structure above ground - which is "typical of most underground chambers in the area".