One of the oddest bathrooms I've seen was a "nested" bathroom. It was in some random gas station. It was a private unisex bathroom. As you entered the toilet was right in front of you and the sink was on your left, but in the far left corner (diagonal from the door) there was another room with a door and another toilet.
This is a diagram of the room. Asterisks (*) are used for spacing, lines are walls, ds are doors, Ts are toilets, and S is the sink.
----------
|T**|*T*|
|***|***|
---d--***|
|S******|
--------d-
The first toilet was not covered or blocked in any way. It was not in a stall, it was just sitting there in the open next to this inner room with another toilet. It didn't look like had ever been any attempt to put up a stall.
You'd think that with two toilets it meant that the bathroom was actually not a private bathroom, but the only way that two people could use this bathroom at the same time and not see each other peeing would be if someone went into the inner room first, closed the door, and stayed there until the person in the outer room did his/her business, washed his/her hands, and left, at which point the second person could come out of the inner bathroom, wash his/her hands, and leave.
It was so nonsensical that I actually checked to see if I was dreaming (since I often dream of odd bathrooms if I have to pee while I'm sleeping).