Prisoners, slaves, and others were prepared for sacrifice by being painted blue and sometimes tortured. They were then led up to the top of one of the pyramids. There they were either shot with a volley of arrows or they had their still beating heart cut out of their chest by a temple priest.
8. The Haab
They have three calendars that work in cycles. One of them, the Haab, has a 365 day cycle just like the modern Gregorian calendar.
6. Spanish conquest
Unfortunately many of their writings were lost during the Spanish conquest. Through laborious study during the 20th and 21 centuries much of their remaining writings have been recovered and translated.
Like the Aztecs, Mayans never used iron or steel. Their weapons were made of obsidian, or volcanic rock.
Speaking of teeth, noblewomen filed their teeth into points.
1. Mayan Empire
Nobody knows how the Mayan Empire declined. Long before the Spanish came many of the great cities had already been long abandoned and lay in ruins. Scholars have hypothesized reasons ranging from drought and famine to overpopulation and climate change.