Now the designers in German come with the idea of returning the pee back to the sender by painting water-repelling material with the wall. The wall itself doesn’t have anything special that you can notice but it will return. So watch out guys if you are in German.
Some owners might place a sigh to notice that the wall will return but some might not so it will surprise someone for sure.
With this idea some people might think it is funny but it does help keeping the city clean and be the place where we live with good condition. Everyone should find the place to ease themselves before thinking about peeing the wall of others.