Very interesting stuff @lyubo19, I hope to visit there some day.
You taught me a new word:
Chalcolithic is an archaeological period which researchers usually regard as part of the broader Neolithic (although scholars originally defined it as a transition between the Neolithic and the Bronze Age). In the context of Eastern Europe, archaeologists often prefer the term "Eneolithic" to "Chalcolithic" or other alternatives.
U&R