Egyptian officials revealed the discovery of a mysterious, 30-foot-long corridor sealed off inside one of the Pyramids of Giza on Thursday.

Egyptian Minister of Tourism and Antiquities Ahmed Issa described the discovery in a Thursday press event, saying the chamber is thought to be some 4,500 years old. The corridor, which lies above the main entrance to the Pyramid of Khufu, is nearly 30 feet long and roughly 6 feet wide.

The area went undetected by archeologists for hundreds of years and was only discovered now thanks to modern scanning equipment. Issa credited the international Scan Pyramids Project (SPP) for making the find.

Experts do not yet have an explanation for why the corridor was made. Christian Grosse, professor of non-destructive testing at the Technical University of Munich and a leading member of the SPP, said they hope the corridor will lead to further discoveries.

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‘’There are two large limestones at the end chamber, and now the question is what’s behind these stones and below the chamber,’’ Grosse said.

The Pyramid of Khufu is named after the fourth dynasty pharaoh who ordered its construction, from 2509 to 2483 B.C. The Pyramids of Giza and other remnants of ancient Egypt are responsible for a large portion of the modern Egyptian economy, bringing tourists from all over the world.

The Associated Press contributed to this report.