By 
The public restrooms at Rock City are made out of rocks.
I saw this passageway in the outhouse wall and it reminded me of those little cubbyholes in the walls in the doctor’s restrooms for urine samples (!), but Dave said, nah, it’s just a fresh air vent.
And those rock-solid outhouses do need fresh-air vents.
I like the colors and textures of the stone and the wood in the close-up shot.
LOL, Cheryl, that cracked me up.
Janet
It cracked me up too. I do like the vent idea though. I would have probably had in mind a “peek hole” and would have put something up there until I was finished.