Around 5000 BC, Sumerians built uruk, which is the oldest city in the world.

At the same time, public buildings such as schools and libraries are also set up.

The oldest existing flood record was written by Sumerians on clay tablets.

Libraries at that time, unlike the books we see now,

But clay tablets. Make the mud into a board and write it on the wet board.

After drying or drying, it becomes mud. The writing on it is cuneiform.