It's not often that a single discovery can illuminate both the history of science and ancient office culture—but that is what happened in the ancient Mayan megacity of Xultun, in present-day Guatemala. There, researchers from Boston University and the University of Texas unearthed a small room, two walls of which were marked with astronomical tables predicting movements of the moon, Venus, and Mars. The calculations seem to have been plastered over several times, indicating that the room was used for several years and that the calculations were refined over time. The earliest of the numerical murals, created in the ninth century, are the oldest Mayan astronomical tables ever found, and the place where they were created is the first documented Mayan office space.

Most Mayan calendars have been found on monumental buildings in public spaces. The Xultun chamber, in contrast, was probably a place where scribes copied tables or made calculations. "The room was basically a work space for an ancient scribe and astronomer who made notations on the wall next to him," says David Stuart of the University of Texas at Austin, who coauthored a paper describing the find in May. The news from Xultun was doubly surprising because the site had been heavily looted in the 1970s and was seen as an archaeological lost cause. But in 2010 a student working in a tunnel originally dug by a looter uncovered a bit of a painting, leading to the discovery of the full work space.

For the record, the Xultun murals further debunk the popular notion that the ancient Mayans predicted the end of the world in 2012. Stuart notes that the tables reference dates 2,000 years into the future, showing the Mayans were quite confident that the clockwork of time would keep going just fine.