I think the subterranean chamber of the Great Pyramid could have been 'discovered', in its original form, in very deep antiquity - in the region of 20,000 years ago.
The site was built upon over millenia and took its present form, complete with casing stones, before the sudden end of the last Ice Age.
I think the two other Giza Pyramids are of similar age and also 'entomb' vastly old sacred spaces.
Edited 1 time(s). Last edit at 10-Jan-18 17:31 by Harry Wolf.