5 Astonishing Forgotten Civilizations

Ertruria
https://en.wikipedia.org/wiki/Etruria
https://www.britannica.com/place/Etruria-ancient-country-Italy

The Khmer Empire
https://en.wikipedia.org/wiki/Khmer_Empire
https://www.encyclopedia.com/history/encyclopedias-almanacs-transcripts-and-maps/khmer-empire
https://www.thoughtco.com/angkor-civilization-ancient-khmer-empire-169557

Çatalhöyük
https://en.wikipedia.org/wiki/%C3%87atalh%C3%B6y%C3%BCk

Erlitou Culture
https://en.wikipedia.org/wiki/Erlitou_culture

The Sea Peoples
https://www.britannica.com/topic/Sea-People
https://en.wikipedia.org/wiki/Sea_Peoples