This is a region with one or more large cities as well as small towns and the surrounding rural area, whose economic and social structure is primarily oriented towards the large cities, which act as the centers of these regions.

The region with the largest population can be found in Japan. The city of Tokyo has a total of 35.7 million people living in an area of 13,556 km². This is followed by the South Korean city of Seoul with 25 million inhabitants, the Brazilian capital of Sao Paulo, which has 21 million people, and Mexico City with a population of around 20 million.

This term is used to describe particularly large cities, often the capital of a country or province. In modern times, international relations are a decisive criterion. Cities of this type function as the social, cultural, political and economic center of a country. In a European context, they are considered pioneers when it comes to social or economic innovations.

In Germany, there are twelve such significant areas. These include the Rhine-Ruhr, Berlin-Brandenburg, Munich, FrankfurtRhineMain, Stuttgart, Hamburg, Hanover-Braunschweig-Göttingen-Wolfsburg, Nuremberg, Central Germany, Northwest, and Rhine-Neckar regions.

Often the name "City of Angels" is associated with Los Angeles, California. However, this is only an epithet - the city whose name bears this literal translation is Bangkok, capital of Thailand. It was built in the 18th century by the then king after its predecessor city was destroyed.