A hidden corridor 9m long has been discovered in the 4500-year-old Great Pyramid of Giza.
The discovery was made by the Scan Pyramids project in 2015 and scientists have been using non-invasive technology to look inside the huge structure. Scientists found the corridor through cosmic-ray muon radiography, which is like a giant x-ray.
Experts have said that the discovery could contribute to knowledge about the construction of the pyramid.
The Great Pyramid was constructed as a monumental tomb around 2560 BC during the reign of the Pharaoh Khufu, or Cheops. Built to a height of 146m, it now stands at 139m and was the tallest structure made by humans until the Eiffel Tower in Paris in 1889.
The pyramid is the last of the Seven Wonders of the Ancient World still standing.