El Morro Fort in Santiago de Cuba -- this particular loophole had a strong smell of urine. Not everyone choses to pay.
Cuba has it's charms. It is also a poor country and like many others the public toilet facilities are commonly pay- to- play.
That is, an attendant or two is stationed outside. You can buy supplies on the way in although the forewarned traveller will have his or her own. You can pay then or drop a coin or so on the way out.
It's better you do as these are the people who keep the toilets clean. It's their job. It doesn't pay well. A nurse makes the equivalent of $30 a month, a chambermaid makes about $10. A public toilet attendant most likely makes much less than that so tips are important to her or him.
Stall walls are half-sized or so. I'm about 5'4" and a good stall covered me from knees to shoulders when standing up.
One of the women on the tour was about 5'10" so everyone knew where she was. She was also sensitive and was too appalled on one occasion to avail herself of the restroom.
Perhaps the toilet flushed, but it fussed about it. Sometimes water, cold, came out of the taps so I could wash my hands, on other occasions I was blessed with soap, too. Hand towels were rare. An attendant may offer toilet paper for drying one's hands.
I used the air.
We're spoiled here. Our toilet stalls as often taller than we are, they are well-stocked, and the hand-washing facilities have hot and cold water, soap, and towels or hand-driers.
We pee for free here and in many cases public toilets flush themselves.
Oh, yeah, I'm grateful.