Lava Cellar in Mendig

http://www.vulkanpark.com/en/volcano-parc/vulkanpark-stationen/route-rot/lavakeller/

http://www.lava-dome.de/staticsite/staticsite.php?menuid=10&topmenu=10

http://de.wikipedia.org/wiki/Lavakeller_%28Mendig%29

http://redesign.larsmay.com/wp-content/uploads/2014/11/Brauereikeller-Fototour-3.jpg

https://www.youtube.com/watch?v=1BbTKfrA_I0
https://www.youtube.com/watch?v=BSdArC1xM4Y
https://www.youtube.com/watch?v=Ica5AtIAQbY