For example has Rome or Ancient Greece written about their origins, that's not based on myth?
The short answer is no.
The reason for this is that the ancient Greeks and Romans – or any other people before the modern era – didn't have professional archaeologists. The ancient Greeks and Romans had little concept of how things changed across time until they started to keep consistent records from about the fifth century BC onwards: this explains why e.g. Achilles is depicted in pottery of the sixth century BC with contemporary clothing, armour, and weapons, rather than stuff from centuries earlier. Heroes of earlier times were almost always depicted in contemporary rather than period-accurate garb: cf. the many reliefs of mythological scenes that date to the Classical, Hellenistic, and Roman eras.
The Greeks and Romans did, of course, find evidence that dated from earlier periods, such as e.g. fortifications that date to what we today refer to as the Late Bronze Age (at Mycenae, Midea, and elsewhere), but they simply fitted them into their own conceptions of how things used to be, rather than try to scientifically reconstruct – as we would do – what the past might have actually looked like. A useful book, that I have cited before, is John Boardman's The Archaeology of Nostalgia, which has the telling subtitle How the Greeks Re-Created Their Mythical Past (published in 2002).
You can also use this earlier reply of mine as a jumping off point. It features lots of links to other answers across AskHistorians. There are also related questions and answers available on my profile page.