13,000 years ago, the Lacher See volcano erupted, so this rock was created. At that time, the Romans cut off large blocks of trass and shipped them across the Rhine to Italy. In the 1800s, trass was mined and processed into a kind of cement in the mills. Today you can see these caves.
October 26, 2017
"The sky in the Brohltal darkened when the Laacher Lake volcano erupted only five kilometers away, and a glowing mixture of lava particles and gases spewed into the atmosphere at intervals, each time the eruptive pillar collapsed, the material raged Ashes and lava particles filled the valleys up to 60 meters high, and the once loose materials of the glut avalanche have, over time, become a rock known as "trass" in our region, which was already built by the Romans In the Brohltal Trass, they used it, among other things, to build a house, adding finely ground lime and water to a mortar that hardens even under water, and it seems likely that it was Dutch people who exploited it in the Brohltal valley since the 16th century Trass is ideal for building dikes and docks, and it was they who gave the name to the volcanic cement: "Tyrass" is Dutch It's called "glue." The walls you see from here are hollowed out and can be visited. Because of their poorer quality, they were no longer interesting for the mining and are today an impressive testimony of the huge glut avalanche that once filled the whole valley. "
October 14, 2019
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