An enormous system of caves, chambers and tunnels lies hidden beneath the Pyramids of Giza, according to a British explorer who claims to have found the lost underworld of the pharaohs [at] the pyramid field at Giza. British explorer Andrew Collins [has detailed] his findings in the book Beneath the Pyramids, tracked down the entrance to the mysterious underworld after reading the forgotten memoirs of a 19th century diplomat and explorer. "In his memoirs, British consul general Henry Salt recounts how he investigated an underground system of 'catacombs' at Giza in 1817," Collins said. With the help of British Egyptologist Nigel Skinner-Simpson, Collins reconstructed Salt's exploration on the plateau, eventually locating the entrance to the lost catacombs in an apparently unrecorded tomb west of the Great Pyramid. According to Collins, the caves - which are tens of thousands, if not hundreds of thousands of years old - may have both inspired the development of the pyramid field and the ancient Egyptian's belief in an underworld. "Ancient funerary texts clearly allude to the existence of a subterranean world in the vicinity of the Giza pyramids," Collins [said]. Zahi Hawass, chief of Egypt's Supreme Council of Antiquities, has dismissed the discovery. "There are no new discoveries to be made at Giza. We know everything about the plateau," he stated. But Collins remarks that after extensive research, he found no mention of the caves in modern times. "To the best of our knowledge nothing has ever been written or recorded about these caves since Salt's explorations.