“Locals chiseled the Guoliang Tunnel into — and through —the side of a mountain.”
What is the difference between “into” and “through” in this context?
I understand that "through" means go into on one side and get out on the other. Yet, I still fail to see the difference between these two prepositions in relation to the side of the mountain.
How would a native speaker picture the scenes if I say "into the side" and "through the side"?