https://www.vice.com/en_us/article/4awp3b/government-scientists-to-scan-great-pyramid-with-cosmic-rays-to-find-secrets

The Great Pyramid of Giza is one of the world’s most iconic and cherished monuments. But though this ancient structure is instantly  recognizable from the outside, its interior is still filled with mysteries, including newly-discovered hidden chambers that have likely remained unexplored since they were built 4,500 years ago.  

Now, scientists involved with the Exploring the Great Pyramid (EGP) Mission plan to use particles forged in outer space collisions, known as cosmic ray muons, to peer inside this monument and resolve its inner structure with unprecedented detail, potentially even detecting artifacts in its secret rooms.