Christaller's Central Place Theory proposes that settlements will be arranged in a hierarchical pattern with higher order central places that provide more specialized services located further apart and dominating larger areas than lower order places. The theory assumes evenly distributed populations, resources, and transportation costs. Central places are arranged in hexagonal market areas. Christaller identified three principles for their arrangement: marketing (k=3), transportation (k=4), and administrative (k=7). While the theory describes observed urban hierarchies, its assumptions rarely hold exactly due to variable factors like transportation costs, resources, and government intervention. It remains useful for understanding trade and service center locations.