A proto-city is a large village or town of the Neolithic such as Jericho and Çatalhöyük, and also any prehistoric settlement which has both rural and urban features. A proto-city is distinguished from a true city in that it lacks planning and centralized rule. For example, Jericho evidently had a class system, but no roads, while Çatalhöyük apparently lacked social stratification. This is what distinguishes them from the first city-states of the early Mesopotamian cities in the 4th millennium B.C. 
Prehistoric Egypt and the Ubaid period of Sumer featured what some call proto-cities. The break from these later mentioned settlements and urban settlements is the emergence of Eridu, the first Sumerian city, in the Uruk period around 4000 BC. A European example of this would be the Cucuteni-Trypillian culture, which dates back to the fourth millennium BC.