World Travel City Photography

Towns and cities have a long history, although opinions vary on whether any particular ancient settlement can be considered to be a city. A city formed as central places of trade for the benefit of the members living in close proximity to others facilitates interaction of all kinds. These interactions generate both positive and negative externalities between others' actions. Benefits include reduced transport costs, exchange of ideas, sharing of natural resources, large local markets, and later in their development, amenities such as running water and sewage disposal. Possible costs would include higher rate of crime, higher mortality rates, higher cost of living, worse pollution, traffic and high commuting times. Cities will grow when the benefits of proximity between people and firms are higher than the cost.
The first true towns are sometimes considered to be large settlements where the inhabitants were no longer simply farmers of the surrounding area, but began to take on specialized occupations, and where trade, food storage and power was centralized. In 1950 Gordon Childe attempted to define a historic city with 10 general metrics. These are:
1. Size and density of the population should be above normal.
2. Differentiation of the population. Not all residents grow their own food, leading to specialists.