International audience In the center of Mexico, on the eve of the Spanish conquest, the human settlements formed around a sovereign received the nahuatl name of atl tepetl (“water/mountain”). The article shows that this pair or difrasismo expresses a concept and supports a political theory. The city is the place of power and the difrasismo, by means of diverse metaphoric movements, indicates clearly the skills of the king: relations with the divinities of the fertility, war, justice and putting in touch with the origins. After the Conquest, the lexical altepetl term which belongs to everyday life speak overrides the complete shape atl tepetl and undergoes a fundamental semantic evolution, which comes along with the politico-territorial reorganization.