This is a sort of companion post to the Life of the City. Unlike that post, this one is focused on the role of memory and history in the conception of the city.
Geographic locations act as memorial cues and assist in building civic memory. Networks of memory attach to loci, forming complex layers of inter-connected meaning. For example: the Roman empire erected civic memorials throughout their urban centers; the physical accretion of these memorials describe maps (the main procession route through which triumphs and other political processions would proceed) in their cities. Arches of triumph and the great pillars (such as Trajan's Column) are the most well known of these memorial accretions. An Arch of Triumph, for example, serves as a cue to remind the citizens of several things at once. The power of the empire is proven by the imperial ability to organize labor and material, reiterated by the triumphal military engagement memorialized on the arch. The soldiers depicted there are generic any-soldiers. Many fathers, husbands, and brothers served in the imperial military machine; seeing these generic soldiers was a way of allowing the memorial to function across all members of Roman society and to join the citizenry together as a sort of single body.
These powerful networks of meanings were intensely important to the ancient world. They were plied by the Greeks and the Romans, the Egyptians and Persians, the Sumerians and all the ancient peoples. They are still applied today: Mary Carruther's great example of the Lincoln Memorial which has become filled with meaning beyond Lincoln as it has survived in collective and architectural memory of Washington DC. It signifies Abraham Lincoln, the Civil War, Equality, and has the marches of time written upon it, perhaps most significantly the "I Have a Dream" speech of Martin Luther King.
As civil spaces acquire these sorts of connections and networks they become further integrated into the life of the city every single square, location, and façade is entered into an endlessly complicated conversation about the history of the locale. When designing cities, these types of stories are important to note. The steps of a temple aren't just "those steps over there." They were created for a specific, often rhetorical, purpose. Those steps are were countless zealots have assembled, the same place where public orations where given and perhaps where traitors where hanged. While PCs and readers can't necessarily be aware of these distinctions (at least not all at once) those who truly inhabit the city earn their spiritual citizenship by being aware of these sometimes conflicting but always overlayed histories and meanings.
In any culture that relies heavily on public ceremony to form memory, and on memory to form collective culture, the steps in constructing civic memorials are probably well-attested and understood. For example, no ancient culture would simply demolish something they wanted the citizenry to forget (or if they did, their strategy would not be complete) because instead of being forgotten it would be remembered as both complete and constructed AND destroyed. The ruin of the building would be a memorial cue that reminded the viewer of the building as it once stood. Instead, semantic networks are changed and overwritten, new buildings can be raised on the foundations of the old, one temple may be consecrated into the religion of another, etc. Semantic change is far more important a tool than the pick or the axe.