Particles Reveal Hidden Rooms

In 2017, an international team of physicists made headlines: they had found a huge empty space hidden inside the Great Pyramid of Giza. The void is roughly thirty meters long, sits just above the Grand Gallery, and had gone unnoticed for about 4,500 years.

The astonishing part is how they found it. No one drilled a hole or moved a single block. Instead they used muon tomography, which tracks tiny particles raining down from the sky as they pass through solid stone.

Egypt has not yet approved any physical entry, so what the room held, if anything, is still unknown.