What do cities have in common terms of location?

- Crossroads of trade routes: This has been a key factor in the development of cities throughout history, as it allows for the exchange of goods and services between different regions. For example, many of the world's largest cities, such as London, Paris, and Tokyo, are located at the intersection of major trade routes.

- River or coastline: Access to water is essential for human survival, and cities have often been built near rivers or coastlines to take advantage of this resource. Rivers and coastlines also provide a means of transportation, which can help facilitate trade and commerce. For example, many cities in the United States, such as New York City, Chicago, and Los Angeles, are located on the coast or along major rivers.

- Natural resources: Cities are often built in areas with abundant natural resources, such as minerals, timber, or fertile land. These resources can be used to support the city's economy and population. For example, the city of Pittsburgh in the United States was built on the banks of the Ohio River, which provided access to coal and other natural resources that were essential for the city's steel industry.

- Favorable climate: Cities tend to be located in areas with a climate that is conducive to human habitation. This can include factors such as temperature, humidity, and rainfall. For example, many cities in the Mediterranean region, such as Rome, Athens, and Istanbul, are located in areas with a mild climate that is ideal for human habitation.