Johannes Brecht playing live in huge (11000 square meters) cave: Aven d’Orgnac, south of France, for Cercle.
Aven d’Orgnac is a cave located near Orgnac-l’Aven, in the Ardèche département, France. it was discovered in 1935 by Robert de Joly and has been open to the public since 1939. It is one of the most visited attractions in the area. Wikipedia