Jimmy Hoffa's buried under Giants Stadium
The conspiracy: Notorious labour leader Jimmy Hoffa, who was said to have had Mafia ties, was killed and buried underneath the end zone at Giants Stadium.
The theory: Hoffa, an organizer with the U.S.-based International Brotherhood of Teamsters union, often engaged in illicit interests, and was once sentenced to 13 years in prison for convictions of jury tampering, attempted bribery and fraud. After his release, though, Hoffa was said to be meeting with two Mafia leaders at a Detroit restaurant when he mysteriously disappeared in late July, 1975. Around that same time, Giants Stadium, the ex-field of the New York Giants and Jets, was being built, and many claimed the mobsters buried Hoffa underneath the arena during its construction. Hoffa wasn't officially declared dead until 1982, but no real merit has ever been found to suggest he rests below the since-demolished field. Though Hoffa's body has never been discovered, the TV show "Mythbusters" proved there was no trace of a body underneath the New Jersey stadium.