Wondering if there chapel is just the tip of the iceberg and there are catacombs going miles deep inside the volcano.
I bet there probably is :}
If that's not the epitome of "omg sum1 needs 2 map dat", I don't know what is.
Speaking of
quakeable churches in France, I give you
The Black Cathedral (actually it's called Clermont-Ferrand Cathedral)
http://i.imgur.com/tdaUARQ.jpg
http://i.imgur.com/1jt62CZ.jpg
http://i.imgur.com/kITGs50.jpg
The reason it looks like some kind of Elder God shrine is because the town of Clermont-Ferrand is surrounded by volcanoes and the entire cathedral is built out of
black lava stone.