First,
The terrain is really freaking great. Rocks color texture, all of it.
As far as the abby goes, it does not make sense to me. I mean, where it is with no road and no other structures, it does not make visual or logical sense.
But, the idea makes sense and I like it a lot. I think you need to use a structure that would be built way up there where no one can get to, think monks. Or if you are sure you want ruins, use something where one would find an 'oracle'.
But if the abby is what you want, move it done to the open space lower right (don't hide it in the back) and give some indication of how the building was used; remnant of a path/road.
IMO based on the rocks and colors and feel. The location you currently have the abby would suit a fortress much better. But should still have a road/path to that peak.
Just what I think.