Acid Swamp Canyon.

Shi Lang looked down at the great canyon and frowned. The place was flowing with thick, acidic water. The entire place was stinking, and he was thinking about how to locate the bandit village hidden in this place. The canyon was spread over a landmass of five hundred kilometers, and that was the only place humans have ever discovered. 

At the end of the canyon was an inactive volcano. That place was the root from where the acidic swamp originated. That volcano was desolate. Forget about humans; even spirit beasts did not venture around it. The only thing capable of surviving in that place were the scattered stalks of black cotton orchids. 

Shi Lang could not comprehend how this worked, but life was miraculous. This herb had no significant quality, and the people did not search for it. Black Cotton Orchid could leave a person paralyzed upon touching it. It was said that some ten-year-old orchids were so strong that they could stun a person from a twenty-meter radius.