Xia Mountains are dangerous.
Almost everyone agreed on this point because they had seen how miserable those people who tried to breach inside. Those who managed to survive would have their mental disturbed because they said that the mountain was so scary.
It had countless traps.
And there were a lot of skilled assassins resided in that area.
The four kingdoms had tacitly agreed to let Xia Mountains alone because they didn't think that it would be possible for them to subdue Dark Moon Organization without sacrificing a lot of their soldiers.
Not to mention, Dark Moon Organization was not alone there.
There were some tribes who lived deep in the mountains.
Then, there was also the mountain tribe who lived at the far west area, which was within Zhang Xu Kingdom. They had been staying still inside the mountain but even those from Zhang Xu Kingdom didn't dare to get close.
Those people were savages.