After walking in the cave, illuminated by dim lights, for about 10 minutes, we descended onto a steep path built into the sheer cliff, which leads to the bottom of the sinkhole.

Water, trickling down from the upper part of the cliff, dampened the path and nurtured different kinds of shade plants, such as ferns, which grew rampant. So we had to be very careful while descending.

Right on the cliff, halfway to the bottom, I could see the elliptical sky framed by edges of the 300-meter diameter sinkhole, which has a depth of 280 meters, and, at the bottom, a diameter of 280 meters. Due to the shape of the sinkhole's opening, it is named hou'er, meaning "monkey's ear" in Chinese.

I could see a dense canopy of trees covering the sinkhole bottom like a green carpet, bordering a small pond of emerald water. I couldn't help wondering how they managed to grow so well in such a secluded space.