Invention with no Inventor

Well I don't know if this falls under the category of "cool fact", but it certainly is a random fact. Over the past week I was a part of a conversation that had to do with the brilliance of human's and their inventions. Things like the "light bulb", "postal service", "automobile", and "Internet". It was then brought to my attention that with all of these great inventions, we know who invented them. We even know a little bit of back story on some of these remembered individuals. Even with all of this there is one great invention in which we do not know where the idea came from or who came up with it. That is the invention of the "toilet". Or more specific, indoor plumbing, and running water. What we do know is that the Romans had plumbing in ancient Babalonia, using lead pipes. The word plumbing came from the latin word Plumbum, which means lead. As far as I can tell, that is the farthest back the invention of plumbing can be traced.