Scientists in Egypt announced in November that they had detected a previously unknown “void” inside the Great Pyramid of Giza. It was the first time since the 19th century that a major interior structure was found within the 4,500-year-old pyramid, which is located along the Nile River a few miles from Cairo, Egypt.
To make the discovery, the archaeologists used special detectors that “see” high-energy subatomic particles called muons. The same technology may make it possible to find hidden features in other archaeological features.
Very interesting information regarding pyramids...it is amazing how advanced in the planning and engineering of these structures well ahead of their times...