Integration and coherence within a city’s physical structure have become an issue for towns and cities as they rapidly expand, incorporate new elements, and undergo incessant changes. At present, we are facing an extensive accumulation of signs and traits in modern urban patterns; many unaccustomed to and incongruous are affecting the socio-cultural and physical characters of cities. Here, we will be discussing whether it would be feasible to create a system of domestic signs which would reflect domestic social values and mental images held and entertained by citizens, and thus to re-create the sign system of cities. We will also discuss factors involved in interpretation of signs and symbols within a city structure. To prevent emergence or exacerbation of contradiction and disunity within syntagmatic urban structures which have been formed through centuries, we must acquire the knowledge and skill necessary to contain the newly adopted elements and assimilate them into a meaningful and coherent whole. In line with this goal, we have conducted a study of changes of physical structures of the city of Yazd through time (a diachronic analysis) with the aim of identifying sustainable parts of the city’s sign system and with an emphasis on the extent in which it has been formed. The questions which were the motivations behind this work and which we will be trying to answer are: Can the sign system within a city be used as a means for creating an alternative structure within the city’s physicality? Is the sign system (as a tool) characterized by specific patterns on whose identification the coherence of the physical structure of a city depends? How can we achieve an appropriate paradigm within an urban sign system? Here we will try to identify processes of integration of modern urban structures into a city structure, and we will do it through combining views held by semiologists with the ideas of urban incongruity and contradiction, which arise as a result of introduction of modern structures into old cities. To transform the medley into a coherent entity, we need to be aware that cities possess markedness. To this end, we have employed the structuralist analytical method with an emphasis on identification of syntagmatic structures (identifying the structural elements and their relative positions within a city) and of paradigmatic patterns (the ways in which elements substitute for or replace one another). Our main aim here is to extend the scope of studies of urban semiology and introduce analytical tools including the use of structuralism theory in the analysis of urban patterns. We have conducted an in-depth analysis of subjective and objective causes of appearance of signs within cities. We have then conducted case discussions as well as discussions about backgrounds and have tried to establish past and current trends of these signs and symbols in Yazd. Extended data were analyzed based on theoretical notions, paradigms and principles governing systems of signs and symbols have been sought.