A bit out of the period of our purview, but of interest for those first classes of Classical Civ:
The oldest stone wall in Greece, which has stood at the entrance of a cave in Thessaly for the last 23,000 years, has been discovered by palaeontologists, the ministry of culture said Monday.The age of the find, determined by an optical dating test, singles it out as “probably one of the oldest in the world”, according to a ministry press release.
“The dating matches the coldest period of the most recent ice age, indicating that the cavern’s paleolithic inhabitants built it to protect themselves from the cold”, said the ministry.
The wall blocked two-thirds of the entrance to the cave, located close to Kalambaka, itself near the popular tourist area and monastic centre of Meteora in central Greece. Greek palaeontologists have been excavating the site for the last 25 years.