Basement of Lava - Lava-Dome Museum

In the city of Mendig you can visit the museum Lava-Dome, which explains the phenomena of volcanoes. It is interesting to see and the entry includes an audioguide (only in English, French and German). What is really interesting is what is called the "lava basement" (Lavakeller), a set of underground galleries dug by man, 32 m. deep. They are unique in the world and cover a superfecie of about 3 square km. They were excavated to extract basalt lava stone that was used for construction. The gallery entrance is next to the museum and can be visited only with a guide (there is one daily visit on weekdays and on weekends, three).