A privately run museum inside the Cité dedicated to the Cathar persecution and the Inquisition that followed it. The reproductions of instruments and the dim cellar rooms tip into the macabre — it is a working tourist attraction rather than a serious history museum.
Still, the basic story it tells — the Albigensian Crusade, the burnings, the long medieval campaign against southern dualist Christianity — is important to understand if you are going to make sense of the Languedoc.