In the past it's usually been bushes and the occasional flowerbed depending on how busy it is.
Once when it was empty, but still broad daylight, there was a bin on the walking path, so I just unzipped my jeans, whipped it out and peed directly into the bin. Steam was rising out of it. I quickly had to finish up so I just pushed my pee stream out hard and I could hear my pee splashing against some cans and the binbag. Quickly zipped back up and a few seconds later someone started walking down the path, so that was lucky!
It was like one of these shapes but made of metal I think