There could have been a giant hill possibly at the time and it was carved out. Or if not that, what's so hard about believing, like what you are saying, they were able to make sandstone blocks out of a slurry and casted in place? It's always been odd how people think it was impossible but don't understand our history has been heavily redacted and it's misdirection to create alien theories about this. These people were highly intelligent.
There could have been a giant hill possibly at the time and it was carved out. Or if not that, what's so hard about believing, like what you are saying, they were able to make sandstone blocks out of a slurry and casted in place? It's always been odd how people think it was impossible but don't understand our history has been heavily redacted and it's misdirection to create alien theories about this. These people were highly intelligent.