Since 1982, a radio frequency emanating from Russia has been broadcasting a buzzer-like sound and, periodically, an unknown voice reads orders, names, and numbers. No one knows where exactly it is coming from or what it means.
13
There is a mysterious and loud radio signal known as 'the space roar' that has yet to be explained.
15
There is a 600 year old 240 paged book called the Voynich Manuscript, that’s written language is still completely unknown today.
15
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.
78