Excellent suggestion. I haven't watched it yet but I'm planning to do it during the summer. There's a few more I plan to watch during the summer in the hope that they don't disappoint my expectations.i searched some old french series on the subject and i found "l'ile aux 30 cercueils". have you seen it, toni ?
Up to now my ratings:
La poupée sanglante: 8.5/10
Le compagnons d'Eleusis: 8.5/10
I don't want to rate Belfagor and Les compagnons de Baal. I don't really like them but I understand that they are sort of precursors and TV series in the 60s had pretty different atmospheres.