The exact cause of death and burial site of Genghis Khan is unknown, because all of the 2000 funeral guests and 800 soldiers were killed in order to preserve the secret.
16
There is a 600 year old 240 paged book called the Voynich Manuscript, that’s written language is still completely unknown today.
15
In 1958, a nuclear bomb was lost somewhere along the swampy coast of Georgia. Its whereabouts remain a mystery to this day.
29
Scientists lit a cave of natural gas on fire in 1971 expecting it to only burn for a few days; it still burns to this day. It has been nicknamed "The Door to Hell".
19
There is an island near Italy that was the site of wars, a dumping ground for plague victims, and an insane asylum. It's considered so dangerously haunted that the Italian government does not allow public access.
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