The Eifel region is the eastern part of the medium-high Eifel-Ardennes-plateau. It is located north of the Moselle river and West of the Rhine. The largest part is located in Germany and a small part in Belgium. The highest point is the so-called 'Hohe Acht' (747 m). In the tertiary period vigorous volcanic activity took place in the Eifel. The craters, caused by explosions of volcanic gasses have filled with groundwater and are called ‘Maare’. The last eruptions took place 10.000 years ago. Research indicates that this area is still geologically active: the whole Eifel area is rising 1 to 2 millimeters every year. In the past there have been inactive phases for 10.000 à 20.000 's years, which leads to the assumption that future eruptions are still possible.