The discovery of some tombs which is important to archaeologists' understanding of ancient Egypt is the discovery that the people who built the pyramids were paid workers, and not slaves. Egyptian archaeologists have discovered a set of tombs which are believed to belong to workers. Experts believe the workers died building the Great Pyramids of Giza. They were workers because the material of the tombs were made of mud brick which was commonly used for the tombs of paid workers. These tombs were built beside the king's pyramid.