Kryptos
A coded sculpture at CIA headquarters has yet to be fully broken.
(This video is no longer available for streaming.) The most enigmatic of all codes in the most clandestine of all places has yet to be fully broken. "Kryptos," a coded sculpture in the courtyard of CIA headquarters in Langley, Virginia, contains a long string of seemingly nonsensical letters that conceal a message devised by sculptor James Sanborn. Some portions have been deciphered, but the last bit remains a mystery. Solutions anyone?