Around 450 BC. Herodotus went to Egypt, where he collected information about the Great Pyramid.
The knowledge he gained he wrote down in his work titled "The Histories". Herodotus describes the history of the tyrannical pharaoh Khufu, who led to the construction of the pyramid thanks to the work of 100 thousand slaves. At that time the Greeks believed that only cruel tyrants were able to build such magnificent buildings. According to his records, the construction took 20 years. He described the existence of mythical chambers under the building, an underground lake connected to the Nile through a channel and an island on the lake, where Cheops was buried.
The information Herodotus obtained most likely came from Egyptian lower priests and local residents. At the time of Herodotus' visit to Egypt, the pyramid had already stood for over 2000 years, so it is worth remembering that verbal transmissions must have contained a lot of inconsistent and not necessarily true information.