What do both John and the reader come to realize about the setting?
At the end of the story, both the reader and John realize that The Place of the Gods was not a place where Gods lived at all. The people of John’s culture have lived for a very long time believing that the Gods lived in the faraway city. To them, it is a forbidden place, a place where demons and spirits live. When John realizes he must go, his father tells him: “It is forbidden to travel east. It is forbidden to cross the river. It is forbidden to go to the Place of the Gods. All these things are forbidden." John goes anyway.
Once he reaches the city and describes it as he walks along, the reader understands through the clues given that this is New York. John describes various places such as the subway and Grand Central Station that let us know this. Eventually, he has to seek shelter for the night, so he climbs to the top of a skyscraper and goes into a penthouse apartment. As he looks out over the ruined city and describes the Burning Time, the reader realizes that the burning time was the result of a nuclear bomb. At this point, John discovers the corpse of a man sitting in a chair. This is the moment he realizes the “gods” he had grown up fearing were really just men. He takes this knowledge back to his father, who tells him not to tell the people because :"Truth is a hard deer to hunt. If you eat too much truth at once, you may die of the truth.” John uses his discovery to begin rebuilding civilization.