First time accepted submitter eionmac writes "The BBC reports that Archaeologists believe they have discovered the world's oldest lunar 'calendar' in an Aberdeenshire field. Excavations of a field at Crathes Castle found a series of 12 pits which appear to mimic the phases of the moon and track lunar months. A team led by the University of Birmingham suggests the ancient monument was created by hunter-gatherers about 10,000 years ago. The pit alignment, at Warren Field, was first excavated in 2004. The experts who analyzed the pits said they may have contained a wooden post. The Mesolithic calendar is thousands of years older than previous known formal time-measuring monuments created in Mesopotamia. The analysis has been published in the journal Internet Archaeology."