Worm King · Lu Da presented some photos and videos.
The Yellow Sand Barrier is considered a relatively primitive and low-cost means of protection, composed of some low-level engravings; even Level Two civilizations can use this method.
Lu Yuan sighed lightly, carefully observing the photos. This settlement is quite large, covering a total of 20,000 square kilometers. Theoretically, a Sky City shouldn't occupy such a large area of land.
"King, according to our reconnaissance, besides the Yellow Sand Barrier, there might also be optical invisibility."
This is a method of achieving optical invisibility through the distortion of light, already within the realm of a Level Three civilization!
"How did you determine the Human Alliance is in this settlement?"
