What is key to realise about this excellent story is the way that point of view impacts everything. The first person point of view means that we only see the action from the perspective of John, the narrator. Of course, as the story progresses, we begin to see what a partial and unreliable view his perspective is, as he represents a future descendant of humanity that has lost memory of what our age today looks like. Thus it is that given the various taboos and lack of knowledge of John's society, he is frightened and scared of the Place of Gods. Consider the following paragraph:
It felt like ground underfoot; it did not burn me. It is not true what some of the tales say, that the ground there burns forever, for I have been there. Here and there were the marks and stains of the Great Burning, on the ruins, that is true. But they were old marks and old stains. it is not true either, what some of our priests say, that it is an island covered with fogs and enchantments. It is not. It is a great Dead Place--greater than any Dead Place we know. Everwhere in it there are god-roads, though most are cracked and broken. Everywhere there are tehruins of the high towers of the gods.
Thus what John sees as being a "Dead Place," we can recognise as being the remnants of New York. What John describes as being "god-roads," we see as being former highways. John's beliefs and world view automatically dictates the way in which he looks at the sights around him, and help him to interpret what he sees. The point of view helps relate that to us.