For 7,000 years, volcanic basalt lava has been extracted from the landscape between the Rhine and the Eifel. Until the mid-19th century, it was primarily processed into grinding and millstones, but since then, the production of building stones for roads, bridges, and houses has taken precedence. This illustrated book documents the development of basalt lava extraction over the past two centuries through more than 200 mostly unpublished images - from the ancient millstone operations of the 19th century to the modern basalt lava industry of today. Impressive photos highlight the technical changes in the quarries as well as the social transformations in the families of stonecutters and stonemasons. Hans Schüller, an employee at the Mayen city archive and a member of the Historical and Antiquities Association, is a profound expert on local and regional history.