The theory of central places is a deductive geographical theory developed by the German geographer Walter Christaller (1893–1969), presented for the first time in his work The central places in southern Germany of 1933 and which would become one of the essential theories of the new quantitative geography.[1]​.

Christaller initially applied this assumption only for the analysis of markets, which is why he excluded highly specialized cities such as mining settlements from the model.

Starting from an isotropic space with a homogeneous distribution of population and purchasing power, the cost of the product will increase depending on the distance and price of transportation factors. In the same way, the population's purchasing power for a product will decrease depending on its cost and therefore distance. Following this reasoning, it follows that there will be a limit beyond which it is no longer profitable to acquire a product or service as there is another closer location.

This systems theory attempts to explain, based on certain general principles, the distribution and hierarchy of urban spaces that provide certain services to the population of a surrounding area in an isotropic space.

To this end, it establishes the concept of "central places" to the points where certain services are provided for the population of a surrounding area.

It is based on the premise that centralization is a natural principle of order and that human settlements follow it. The theory suggests that there are laws that determine the number, size and distribution of cities.

Christaller's theory creates a network of circular "areas of influence" around the service centers or central places that in the model end up becoming hexagonal tiles as this is the geometric figure closest to the circle, which does not leave interstitial spaces uncovered when gravitating towards one or another nucleus.

The existence of central places that offer a greater and more varied range of services allows us to deduce a hierarchy of nuclei, creating areas of influence and relationships between them.

Following the geometric model") we see as always the number of central places must be a multiple of 3. If we stick to the transportation network we manage other variables: access and cost of travel, so the number of places becomes a multiple of 4. But if the region is a border, the number can be up to a multiple of 7.

Christaller, W. 1966. Central Places in Southern Germany. Prentice Hall, Englewood Cliffs, New Jersey. (Translated by Carlisle W. Baskin).