Henry Lincoln Chronicle ; BBC; 1979.

I never actually saw this programme when first broadcast, as I was living in Holland in 1979.  But 3 years later HL published Holy Blood Holy Grail with his co-authors Michael Baigent and Richard Leigh!  Here he introduces the pentagonal geometry he found in the area round Rennes Le Chateau, which I eventually picked up on and the majority of this Blogspot is devoted to!  https://www.youtube.com/watch?v=-bYKaXJVt6k&ab_channel=HenryLincolnSpeaks