The Eifel is "rich in stone".

The Eifel is "rich in stone". The mining of special stones in the Eifel has been documented since Celtic times: Basalts for grinding and millstones. In the Middle Ages, numerous churches & monasteries were built from Eifel stone. After the World War, the cities were rebuilt on a large scale using pumice stones from the Laacher See volcano. Within sight of the Pulvermaar stands a volcanic mountain that ejected a lot of "cinders" and "bombs": lava in red, yellow, grey to black. At Pulvermaar itself we find ash & lapilli as ejecta en miniature. Most of the bombs have a core and keep a secret, the rare ones even made of crystals (semi-precious stones). To take all these shapes & colours in your hand and to distinguish them from slate, greywacke, sandstone, lime etc., that should be possible here in a playful way. Of course, the story is also told about how and when these stones were formed: a short journey through time from 400 million year old slate to a volcano that is only a few millennia old.
Suitable for all ages.