Chakravanti wrote:non of those ideas address building a wall through a cliff.
You're trying to do something that doesn't make sense to me... I could see people moving the cliff out of the way a bit so that the wall can go around the cliff, I could see people building some sort of gonzo wall that goes right up the cliff face, but through it?
As if there was just a hole in the middle of the ridge where the ground didn't change height?
Just sounds weird.
Walls through rivers/lakes sounds more realistic to me (and that one doesn't sound easy either)