As any history nerd knows, the past is full of crazy stories and larger-than-life figures who helped pave the way to our modern world. But perhaps the most riveting thing about it is the number of unsolved mysteries scattered across the history books like nerd-catnip. It was hard to choose just 20 to feature, but these are our absolute favorites of all time. Did we miss any uncracked cold cases that you're obsessed with? Share them with us in the comments!