Found this on our roadside America app. Its worth a stop but not a long detour. Articles are very fun and informative. It is in a little dedicated park so you can get out and walk around. you cannot go inside.
If you are driving by Gays, Illinois you MUST make a five minute stop to see this structure. The outhouse is locked so no peeking inside, but you are looking at a legitimate two story outhouse that once serviced a general store with second floor apartments. Stretch your legs, get back in the car, and be grateful for modern day rest rooms.
The two story outhouse was attached to a mercantile store. The store had apartments upstairs. So the people did't have to go through the store to "go", they could walk out back on a deck to go to the top outhouse. It's really unique.
If you knock on the property owners door they will open the outhouse doors. I got to drop a big ol' turf from 2nd floor. No back splash.
The nice part was that we were on a road trip and doing the roadside attractions and didn't arrive until 1am. We were still able to get out and explore. I had to use the bathroom, but the outhouse isn't open. Ha ha! There are some newspaper articles on a board and a nice little sitting area so it was worth the stop.