Mühlsteinhöhle (Caverna do Moinho) no Nerother Kopf

Height: 643 m above sea level. NHN
The millstone cave consists of lava boards and is an artificial cave in the Vulkaneifel, Rhineland-Palatinate. It was created by the production of millstones from a volcanic rock wall.
The Millstone Cave is located in the summit area of Nerother Head, a wooded hill of volcanic origin just east of Neroth. The entrance is located just below the castle ruin Freudenkoppe at an altitude of about 640 m and is accessible via a hiking trail. The cave is 18 meters deep and its vault up to ten meters high. It is walkable but unlit (flashlight required).
The Nerother head turned out early because of its steep vertical walls of lava panels as a suitable mining site for millstones. The date of commencement of quarrying is unknown, but probably lies before the castle was built around 1340. The millstones were broken out of the rock with a hammer and a chisel and finished on the spot. Unfinished blanks of these stones can still be found on the walls of the cave today. Outside the cave remains of broken millstones can be found. However, the lava rock was not only mined for millstone production, but was also used in the construction of Burg Freudenkoppe use. Even in later times millstones were recovered here again, the last testimony dates back to 1788. Presumably, the cave was larger at this time and also included a side exit, slipping earth but moved a part of the cave. According to a legend, the cave was even part of an underground corridor to other castles, which is also in the popular poem Op the Nerother Kopp / there sits the Deuwel drob / drives under the ground through / to the Altburg is expressed.
In the cave members of Wandervogel e met on December 31, 1919. V. to found the Nerother Wandervogel.
Since 1980, the cave is under protection as a cultural monument

Impressive cave. Does not come across so great in the photos. Must have seen when traveling on the Eifelsteig.

Very interesting with castle ruins and cave