[Zigûr]

I think the worst parts of these videos are always the Tolkien dilettantes in the comments who shout "Appendices!" as the magic word for anything seemingly divergent from the source material. I'd be curious as to how many have actually read them.
I'm already sick of Radagast. His presence and the invention of his adventures in these films in my opinion diminish the unique determination and heroism of Gandalf.
I can't help but feel that these "Ringwraith tombs" and similar plots exist because the filmmakers are too lazy to find ways to explain Middle-earth's history properly. History is so important to the story, and in The Hobbit especially when it is put into context with The Lord of the Rings. There must be ways of presenting it in a meaningful way. Professor Tolkien's view of history is so focused on the connection of events and how this is viewed and interpreted within the story, not just arbitrary supernatural occurrences popping up to renew characters' interest in some mystery.