Last fall, when researchers unearthed the remains of a 3,000-year-old structure in the western Armenian town of Metsamor, they faced two mysteries: First, they didn’t know what purpose the structure had served. Beyond that, a strange powdery substance covering the area left them stumped...The team assumed, at first, the material was simply ash. After all, charred remnants of the building’s reed roof and wooden beams indicated it had met its end in a fire...The powder wasn’t ash, but wheat flour. They had unearthed an ancient bakery.Archaeologists estimate that the structure could have once held as much as 3.5 tons of...