[beeandapenguin]

The Sphinx wasn't built with stone from a quarry, it was carved from the bedrock. It has since been restored a number of times, one of which added layers of limestone block which is easily distinguishable from the original shape.

[lodovic]

Flint Dibble explains it a lot better than I can, around 11:00 in the video: https://www.youtube.com/watch?v=oITaI2kDIFI