At the top of the mountain that the Battle Maiden Sect is on stood a building. This building wasn't too large, maybe about 5,000 square feet, but the aura radiating off of the building was more than enough to force anyone from approaching if they weren't strong enough or didn't have permission.
The building seemed to be made out of several different kinds of materials, some of which one could easily tell came from the stones and trees on the mountain.
The trees and stones near the top of the mountain have all been saturated with an extremely dense amount of Qi for countless years and have long become Mystical and Divine Grade treasures.
Thus, it wouldn't be wrong to say that the building standing at the top of the mountain is a Divine Grade treasure in and of itself!