Like a fine sculptors work,
our ancient monuments were created
from the top down.

Viewing the various monuments carved into the living bedrock such as the mysterious Kailasa temple and Ellora Caves, or the temples of Lalibela; also detailed at Jordan's Petra and the Hegra of Saudi Arabia;
its been established they were created working with gravity to remove the stone by starting at the top and working the sculptor-builders way to the bottom.

No doubt the temples of Abu Simbel were created in the same technique; with identical procedure of hewing, carving and creating our ancient monuments from above to below.
The megalithic monumental sculptors message hidden in massive architecture in evidence from the top down, details that the Artisans of yesteryear, were more than hunter-gatherer civilizations with prehistoric tools just advancing from primitive to intelligent life.

https://imgur.com/bqdpZZa