Some folks think the Earth is just 6,000 years old, but if you look at archaeological finds in Mesopotamia, you’ll see a way bigger story. Take the city of Ur in southern Iraq, for example. The Sumerians were way ahead of their time—around 4000 BC, they were already building this awesome drainage system using baked clay rings. These ring-drains helped move wastewater away from homes, kept flooding at bay, and made things a lot cleaner. This clever use of drainage really shows just how innovative the early Mesopotamian societies were and makes you rethink what you know about ancient history.