greg egan visited tehran before writing zendegi:
As well as simply wandering around trying to get a sense of Iranian street life, I had some specific “location scouting” and fact-checking to do. In Zendegi, an escalating series of protests sweep across the country, and the scenes I’d written in the novel’s first draft had been based partly on accounts of earlier demonstrations. But the physical geography of Tehran was changing, and many of the choices I’d made from street maps alone turned out to be absurd. When I went to Enqelab Square – the location of a number of protests in the past – it was a construction site surrounded by fences, with no clear sign of what would emerge there in the future. Enqelab Avenue, where I’d tentatively set one march through the city, turned out to be an obstacle course of flyways, overpasses, and median-strip bus stops.
i thought this culture surprise was interesting too, though i can't think of any particular way it affected the book:
Walking back along the riverbank at dusk, I kept having to avert my gaze from couples lying on the grass – nothing too shocking was going on, but I’m sure they did not want an audience. Having read that morality police could arrest couples merely for holding hands on the street, this was a bit of a surprise; no doubt that has been, and still is, true at various times and places, but in Esfahan in late 2008, no one appeared too inhibited about public displays of affection.