The opening paragraph to the story tells readers what is forbidden to John and to other members of his society.
The reader is told that it is forbidden for anybody to go east.
It is also forbidden to cross the great river.
Lastly, it is forbidden to even look at the Place of the Gods.
John did all three of those things, despite the fact that his father reminded John not do any them.
"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."
Nevertheless, John leaves on his journey. He sees an eagle flying east, which he takes as a sign. Next he sees three deer travelling east, which he takes as another indicator that he is meant to travel east. John goes east. After eight days, John arrives at the great river, which the reader learns is the Hudson. John then looks at the great city across the river. It is the Place of the Gods.
Then I raised my eyes and looked south. It was there, the Place of the Gods.
John is in awe of the city, and he is quite frightened. Despite his fear, and the fact that he is not supposed to cross the river, John builds a raft and crosses the Hudson.