Graham Hancock, renown British writer and reporter and Ancient Egypt enthusiast/historian, believes that the Pyramids of Giza couldn't possibly have been built/constructed with the knowledge and tools that we believe were around during the era. He then further believes there must be a lost chapter within the human story , of an ancient civilisation that was more advanced than would be thought of that time..
Denise Chow, an ancient Egyptian enthusiast believes that the ancient Egyptians used a sled like contraption to haul the blocks of stone that weighed 2.5-30 tonnes of which were used to construct the pyramids. An Egyptian wall painting found in the ancient tomb of Djehutihotep, depicts 75 people hauling a large statue on a sled like contraption of which you can see a person pouring water in front of the sled, supposedly to reduce friction making it easier for the large objects to be pulled. This image is what influenced Denise's Hypothesis on how the large stone blocks were transported, however there is still no answers on how the large blocks were lifted to construct the pyramids.
An Account of Egypt - Written by the historian Herodotus, a Greek historian born in the city of Halicarnassus which is in the south west of Greece. Herodotus was believed to have lived in the 5th century around 485bc and recorded many of his experiences and findings through writing. Herodotus believed that the pyramids where built by slaves serving a merciless pharaoh named Cheops (Khufu), who had taken control after the king Rhampsinitos.
These tombs where found by a tourist exploring Egypt in the 1990's and they are said to be the tombs of Egyptian Labourers. Zahi Hawass was one of the historians to analyse these specific tombs. Hawass believes that the builders were paid labourers, as the tombs were placed beside the Kings and men of royalty. Slaves would not get this privilege (if they were by any means slaves) as they were considered worthless born to work scum . They also discovered a 9ft deep shaft preserved by sand which contained food and drink for afterlife.