What city was considered to be the earliest city in southern Mesopotamia?

Machu Picchu
Stone henge
Eridu was long considered the earliest city in southern Mesopotamia. Located 12 km southwest of Ur, Eridu was the southernmost of a conglomeration of Sumerian cities that grew around temples, almost in sight of one another. These buildings were made of mud brick and built on top of one another.
Zel Pon
Very interesting!