The “Dreisborn” in the upper Prembach valley below the Mosenberg volcanic group is a constantly producing mineral spring, a so-called “Säuerling” (acidulous spring). The “Dreisborn” belongs to the municipality of Bettenfeld.
Soil outcrops on the Wingertsbergwand near Mendig allow science to explain the history of the Laacher See eruption through comparisons with currently active volcanoes.