Scientists believe they've found two more mysterious cavities inside Egypt's Great Pyramid at Giza.
But they haven't been able to confirm it with their own eyes. Using laser scanning, infrared imaging and other non-invasive techniques, the researchers were basically able to peer from the outside in.
The cavities don't appear to be related, and the scientists don't know their exact size, let alone what they were used for.
Hidden rooms have long fascinated many researchers, some have whom have suggested things like Queen Nefertiti's lost tomb being hidden in a room behind King Tut's burial chamber.
Egypt's former minister of antiquities is reviewing the findings but thinks the two newly found "rooms" aren't rooms at all — just oddities in the structure.