CAIRO (Reuters) -A hidden corridor nine metres (30 feet) long has been discovered close to the main entrance of the 4,500-year-old Great Pyramid of Giza, and this could lead to further findings, Egyptian antiquities officials said on Thursday. The discovery within the pyramid, the last of the Seven Wonders of the Ancient World still standing, was made under the Scan Pyramids project that since 2015 has been using non-invasive technology including infrared thermography, 3D simulations and cosmic-ray imaging to peer inside the structure. An article published in the journal Nature on Thursday said the discovery could contribute to knowledge about the construction of the pyramid and the purpose of a gabled limestone structure that sits in front of the corridor.