It's not a normal plain. It's a place where light being live, a sort of paradise if you will. It's supose to be a mix between a city and plain.
It's not a nature area where you simple walk past. Think of it as a very big park of a city, hehe.
As for the thing with the screenshot you made. You're forgetting i am using waterfalls. If i am using a waterfall to change the level of the terrain the upper or lower part should have the same level as the water level, same because that changes with the waterfall, since there is a cliff inside the waterfall too, right?