The human cities were scattered in a small corner of the great wilderness. If one were to look down from the above, one would find that the human race was hiding in a cove.
If one was not told the location of the human race, it would have taken a lot of effort to find them.
After Yuchi left the human race, he started to encounter all kinds of wild beasts in the surrounding mountains and forests. These wild beasts were generally strong.
They had completely blocked the overland traffic between human cities, forcing human cities to reach each other via underground rail.
Without the city's barrier, if ordinary people wanted to live in the wilderness, they would have to live under the constant threat of danger.
In the southernmost part of the area populated by the human race, there was a sea called the Vast Sea.
