Very old artworks provide a fascinating glimpse of ancient life, but not without limitations: They typically portray the lifestyles of the rich and famous (rulers, royals, generals, and priests), abandoning the masses to the mists of history.

That's why the recent discovery of a 1,300-year-old mural at Calakmul, Mexico, is so significant. It is the only known pre-Columbian artwork depicting ordinary Maya engaged in everyday activities, rather than serving the wealthy.