The Longyu grottoes in China are one of the few and clear proofs that mining equipment was used in this area in the past. It was used to create caves and left marks on the vaults like modern harvesters. Examples of these traces can be found in the article: How were the Longueu grottoes built?
It turns out that there are other similar places (grottoes), completely non-tourist ones, which have recently been cleared and studied as far as possible. Although, the locals knew about them for a long time:
About 30 years ago, a certain Xu Jianxin and his father Xu Baosong found caves near the village of Shetang near the city of Lanxi (Zhejiang province in Eastern China) and cultivated mushrooms there for some time. In 2017. Chinese scientists became interested in this place:
Pictures taken on April 18, 2017. This facility is located near the Longueu cave system. The cave was discovered in this form: the arches are very low, obviously inside the alluvial soil, which was brought by the river flowing nearby during large-scale floods. But the presence of stones in these alluvial deposits speaks of some larger-scale event, something like a mudflow in the river bed.
Promotional video:
Pay attention to the vaults, to the ceiling in the grotto - everything is like in the Longueu caves, traces of machining. Such traces in a clear system do not leave a stonecutter's chisel. Such traces are left by a mining machine. The second slide is a close-up shot. The area of this cave system is about 3000 m2.
The system of entrances to the grottoes in this place. They are located in different locations. One entrance has even been ennobled, the others have not yet been studied, because they can only be seen from the river.
And this is what was revealed to archaeologists when they cleared some of the grottoes:
It turned out that the grottoes were once laid by masonry, and inside them were stone dolmens or sarcophagi. It is possible that after the breed was selected, people who came here built a tomb in the grottoes. Either the grottoes were made for this purpose. It would be interesting to know what the Chinese archaeologists found after the excavations …