The first GREEK settlement?
Well probably not since other Neolithic settlements like Nea Nikomedia have also since been found in Thessaly in Northern Greece but its one of the oldest dating occupied for over a thousand years.
Why do I consider this Neolithic settlement to be Greek ?
Note the use of slip and the symmetrical arrangement of the cord used to create a geometric pattern rather than spirals and the overall symmetry.
Now here's a reconstruction of what archaeologists think Sesklo looked like.
MMM terraced hillside and is it a central plaza / agora next to the main building?
Why do I say terrace rather than wall? This is Greece well their ancestors ... the houses are close but separate on a hill to leave slopes and flatter land free for farming and grazing and while many archaeologists believe walls were for defence ... remember there were still four legged predators back then and a need maybe to shelter garden plants from storms and rain and wandering stock .
Perhaps Sesklo should be called a proto polis?