After hearing this, Di Tou's mind had cleared up somewhat, and he found this was indeed a suitable point of inspiration. That day he hadn't paid it that much focus as his main purpose was to run away and save his life, and in that frantic mood he wasn't of the proper mindset to be admiring the natural formation and curvature of the stone walls, especially considering that the structure of the cliff walls was formed by the tunneling and movement of millions if not billions of tiny little bugs.
But now, thinking back, Di Tou seemed to recall that although there were some holes here and there, as a whole the walls were still relatively flat looking. If there was something to note, it was that instead of forming a V from the rift on the surface down to a closing point on the bottom, after one entered the lips of the cannon, the canyon kept expanding, becoming wider the further down one went, forming a /\ instead.