trilogy ever made. They were all filmed at the same time before the first one was ever released. Basically a 9 hour movie. I had known they were shot all relatively close to each other, I just figured that maybe they took 2-3 month breaks. But more importantly they were all filmed before the first release, meaning they couldn't get feedback and studio demands on how to one up the original and go even bigger with CGI, characters, etc....
So yeah...how rare is that? Makes total sense why it's the best trilogy of all time. Think of the disaster the latest Star Wars was with writers, director changes, trying to fix things that fans were mad about, trying to fix directing and story mistakes from film to film. Just a disaster.
Lord of the Rings is one of the great movie treasures of all time. The source material, the time commitment from crew and actors, the dedication, and attention to details probably won't be achieved ever again.