Tübigen, Germany — Archaeologists have discovered four stone that have been painted by humans about 15,000 years ago. It is therefore the oldest known painting ever found in Central Europe. The meaning of the painting is unclear: The stones are covered with several rows of reddish-brown dots. Archaeologists speculate that they might have a shamaic meaning, or that they might simply represent a menstruation calendar. Starting tomorrow you can see the stones exhibited in a special exhibition at the University of Tübingen.