Kryptos is a mysterious encrypted sculpture designed by artist Jim Sanborn which sits right outside the headquarters of the CIA in Langley, Va. It's so mysterious, in fact, that not even the CIA has completely cracked the code.
The sculpture contains four inscriptions, and although three of them have been cracked, the fourth remains elusive (Read what the first three inscriptions say here). In 2006 Sanborn let slip that there are clues in the first inscriptions to the last one, and in 2010 he released another clue: the Letters 64-69 NYPVTT in part 4 encode the text BERLIN.
Think you have what it takes to solve it?