The oldest-known version of the ancient Maya calendar has been discovered adorning a lavishly painted wall in the ruins of a city deep in the Guatemalan rainforest.
The hieroglyphs, painted in black and red, along with a colorful mural of a king and his mysterious attendants, seem to have been a sort of handy reference chart for court scribes in A.D. 800 — the astronomers and mathematicians of their day. Contrary to popular myth, this calendar isn't a countdown to the end of the world in December 2012, the study researchers said.