The Apollo 20 saga is an elaborate hoax began on April Fools Day via a series of YouTube videos. It is about about a covert joint American Russian manned mission to explore an extraterrestrial civilization on the dark side of the moon.
The hoaxers have long since fessed up, the primary perpetrator was French artist Thierry Speth. Despite Speth's admission and proofs of the hoax, many from the tin foil hat crowd insist the story to be true.
The videos are well done, professional quality in many respects, considering the hoaxer is a professional artist.
However, despite the realistic quality of the videos they have been easily debunked. When viewed in their intended sequence, they spin a yarn of the faux mission.