Uh...there's this thing sticking out of our kitchen wall

See, this is what the wall looked like a few days ago.


Today there's this thing sticking out of it.



So, what goes in here? Regular or unleaded?


I have since come to find out that this is so that plumbers can easily get to our sink if it becomes clogged and they have to "snake it". It's common practice to have these outside the wall of the kitchen if you can't easily get to the drain (which we won't be able to do because of the bay windows).

It will be stuccoed (is that a word) over and painted so that it will barely be noticeable. At least, that's the plan. Check back to find out how it goes...