The ancient Mayan civilization is filled with mysteries.  Scientists have struggled for 200 years to unlock the secrets of the hieroglyph writings.  The Mayans had an elaborate calendar system which evolved in complete isolation from those of the old world. This system ended with the fall of the Mayan civilization. Most of the remaining knowledge of it was destroyed by the Spanish during the conquest. It was not until very recently, during the 1990s, that archeologists have finally been able to fill in many of the gaps in our knowledge of Mayan civilization.  The most compelling mystery is the Mayan prophecy of the year 2012.