On August 18, 2010, Ben McDaniel disappeared after diving into a treacherous cave at Vortex Spring, Florida. He was never seen again.

In 1997, author Eugene Izzi was found dead hanging from a 14 story building in Chicago. Was it death, murder or suicide? The evidence is a mystery itself.

Rodney Alcala is a convicted rapist and serial killer sometimes called “The Dating Game Killer.” Alcala may have committed up to 130 murders.

Arguably the earliest instance of a plane whose pilot (and the plane itself) went missing is the 1910 disappearance of an aviator named Cecil Grace.

Grady Stiles Jr. led an interesting life and suffered a death that was just as intriguing. He was known as the Lobster Boy and had even committed murder.

On 10 April 1990, the crew took the Casie Nicole a fishing expedition. Five days later, only one man was found. The crew’s fate is a mystery.

Where is all the Fort Knox gold? Only a handful of people have been inside the vault, and there hasn’t been audit since the mid-1970s.

Building the Parthenon was costly and labor-intensive. Huge slabs of marble had to be moved from Mount Pentelicus, a journey of ten miles.