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 are pictures of Knights fighting Snails in old Medieval manuscripts - and nobody knows why.
23
The Platypus used to be considered a myth like Bigfoot and the Yeti.
18