All sorts of graffiti can be found there :
– lots of them date back to the 14th and 18th centuries ;
– names of streets and squares, written by Abbot Danicourt in order to mark his way through the gallery maze ;
– also names and dates carved by soldiers during World Wars I and II ;
– even more recent inscriptions such as ” Sophie pour la vie. 1992 ” of little interest for the time being.