The documentary about life in the Grande Chartreuse in the French Alps came out in 2005 and I’ve only just managed to see it. Not so slow, really, if you accept what Wikipedia says about it:
The idea for the film was proposed to the monks in 1984, but the Carthusians said they wanted time to think about it. The Carthusians finally contacted Gröning 16 years later to say they were now willing to permit Gröning to shoot the movie, if he was still interested. Gröning then came alone to live at the monastery, where no visitors were ordinarily allowed, for four and a half months starting in mid-March 2002. He filmed and recorded the sound on his own, using no artificial light.
There is no commentary, no sound effects and, at 162 minutes, is not for those who like their movies with multiple explosions and mayhem… But for those seeking a mini-retreat and a glimpse into a very different world, I heartily recommend it.