The Northeast and the area North of the Great Wall are two different directions; the Northeast refers to the east of the grasslands and north of Shanghai Pass. The area North of the Great Wall refers to north of the Great Wall and east of the North Sea—these are two distinct regions.
Ordinary people might not have a clear conception of this, but to put it in one sentence, it's that for thousands of years, no historian has been able to produce accurate data that precisely depicts these two geographical areas.
The farthest place you could walk towards the south is the ends of the earth in Qiongzhou, but heading north, you wouldn't know how far to go; perhaps you'd never see the end.
Ancient people often used terms like "primeval wilderness" or "barbarian wilderness" to describe the outer lands, but to the north, only "wilderness" remains. Past Blackwater River, you wouldn't even see many small animals, let alone people.
