Mr Wawrusiewicz said: “Building dykes, digging trenches, even in our historical times, was not always defensive.
“Sometimes it delimited certain zones – the sacred and the profane.
“The trench, the embankment, was supposed to demarcate the sacred zone with the everyday zone.”
The archaeologist added: “We currently don’t know what these rings are.”
The ancient settlements were discovered using novel techniques that allowed researchers to look back in time without digging up the ground.