“This discovery, in my opinion, is the most important discovery of the 21st century,” Zahi Hawass, Egypt’s former antiquities minister, told NBC News Thursday. ”“The discovery today tells us there is something important to be discovered soon under that tunnel, which could be the real burial chamber of Khufu,” Hawass said. In 2017, scientists using the same technique discovered what they said was the first major inner structure found in the pyramid since the 19th century, when they found a “void” or “cavity” called the Grand Gallery, one of a series of passageways and chambers