The Underground Forests or Crater Forests (Dixia sunlin) are located within the several huge volcanic craters of the Zhangguangcai Mountain Range, northwest of Jingpo Lake. These are all inactive volcanoes today, but the fertile volcanic lava within these ancient craters allows for the formation of these lush forests.  Most of these craters have a diameter of around 400-500m and are as deep as 200m. The third crater is the largest one of the lot.

Travelers can walk down on the stone stairs to the bottom of these well-like craters, finding themselves in another world dominated by precious species of trees and flowers. Probably because of the lava earth at the bottom, the forests are extraordinarily rich. Animals of all kinds also seem to host the place, rabbits, goats, birds are seen everywhere. On top of these, there are a lot of volcanic caves at the bottom of the craters. For some reason, the climate in these caves is abnormal, it is not surprising to see ice in summer, while in winter the caves are extraordinarily warm.

How to get there: From the gate to the Jingpo Lake Scenic Area which is near the Jingpo Shanzhuang Hotel, there are mini buses to the Underground Forest, about 50km northwest. The trip takes one hour.

Not far south of the Underground Forestis a group of "Lava Tunnels" that run down some of the old volcano slopes. The tunnels resemble the limestone caves that are scattered around Guilin, Guanxi province, but they have stranger origins. Scientists estimate that these cave-like tunnels were formed by a major volcanic eruption, sometime between 4000 and 8000 years ago. The surface of the lava flowing down from this ancient eruption cooled and solidified much faster than that within, which continued to be sucked down, straw-like, until the lava was exhausted. The long tunnel walls then hardened and solidified.

The Lava tunnels found today are as long as several hundred meters, and big enough for several people to walk in at the same time. The inside of the tunnels are usually arc-shaped, with ceilings and floors full of lava stalactites and stalagmites of various sizes. Many of these columns are interestingly shaped and are said to resemble various themes, not always identifiable, lit by a ghostly purple light for a mysterious, but a little annoying, atmosphere.

How to get there: the Lava Tunnels are located 13km south of the Underground Forests. Travelers can also take the local tourist buses from the gate near the Jingpo Shanzhuang Hotel.

(Source: ctrip.com / photo: baidu.com)