We don’t know!
Today there are no fire-breathing mountains in the Eifel, however the earth under our feet is moving.

Every year the Eifel rises by around a millimetre. There are innumerable points on the surface where carbon dioxide comes out or disperses in water in sparkling springs known as acidulous springs or Sauerbrunnen.
Geophysicists have discovered that the earth’s crust under the Eifel is considerably thinner than continental crusts usually are and this suggests that there is a hot zone under the Eifel where hot rock can rise to the surface. All of this allows us to conclude that the conditions still exist for volcanoes to form under the surface of the Eifel and that therefore volcanic activity in the Eifel is not extinct, but merely in a dormant phase. Volcanic eruptions are therefore possible. There is no need to worry, however, as the Vulkaneifel is one of the most scientifically researched volcanic regions on the planet and the measuring instruments show no current signs of danger.