There are some historical mysteries that may never be solved, from the date that Jesus was born to the identity of Jack the Ripper to the location of Cleopatra's tomb. Sometimes, that's because the relevant excavated material has been lost or an archaeological site has been destroyed. Other times, it's because new evidence is unlikely to come forward or the surviving evidence is too vague to lead scholars to a consensus.

The lack of answers only makes these enigmas more intriguing.