Hidden corridor discovered in Egypt's Great Pyramid of Giza

Egyptian antiquities officials announced on Thursday the discovery of a hidden nine-meter-long corridor behind the main entrance of the Great Pyramid of Giza that they said could lead to further findings.

The find was made under the Scan Pyramids project in 2015 and has been using modern technology including scans and endoscopes to peer inside the pyramid, the last of the Seven Wonders of the Ancient World still standing.

The unfinished corridor was likely built to relieve the weight of the pyramid on either the main entrance, seven meters below, or on another as yet undiscovered chamber or space, said Mostafa Waziri, head of Egypt's Supreme Council of Antiquities.

The Great Pyramid of Giza

The Great Pyramid was built as a monumental tomb around 2560 BC, during the reign of the Pharaoh Khufu, or Cheops.

It stands at a height of 146 meters (479 feet), the tallest structure built by humankind until the Eiffel Tower in Paris in 1889.

The unfinished corridor was likely created to redistribute the pyramid's weight around either the main entrance, almost 7 meters away, or on another, as yet undiscovered chamber or space, said Mostafa Waziri, head of Egypt's Supreme Council of Antiquities.

"We're going to continue our scanning so we will see what we can do ... to figure out what we can find out beneath it, or just by the end of this corridor," he told reporters after a press conference in front of the pyramid.

Five rooms atop the king's burial chamber in another part of the pyramid are also thought to have been built to redistribute the weight of the massive structure. It was possible the pharaoh had more than one burial chamber, Waziri added.

Scientists confirmed the presence of the corridor using radar and ultrasound, before retrieving images of it by feeding a 6mm-thick endoscope from Japan through a tiny joint in the pyramid's stones.

In 2017, Scan Pyramids researchers announced the discovery of a void at least 30 meters long inside the Great Pyramid, the first major inner structure found since the 19th century.