And since Hale-Bopp was mentioned in the current session, weirdly enough the last time Hale-Bopp was visible before 1997 was also around 2200 BC:
I like this time period.July 2215 BC: Comet Hale-Bopp visits the inner Solar System and would not return until the year AD 1997.
5000 years ago (3000 BC) the territory of modern St. Petersburg was still under water due to the high water level (in the Gulf of Finland, 7-9 meters higher than today). There was no Neva River (and there was no connection between the Baltic Sea and Lake Ladoga). The climate was then 2C-3C warmer than today.
~4000 years ago (2000 BC) as a result of a catastrophic event (melting of glaciers, change in landscape) the waters of Lake Ladoga broke through into the Gulf of Finland, the Neva River was formed. The water level in the Gulf of Finland is 4-6 meters higher than today. The climate was still 1C-2C warmer than today.
3000 years ago (1000 BC) cooling (1C-2C colder than today's climate) and a drop in sea level to modern levels.
So, we have a period from 4000 to 3000 years ago, when the Neva River was already formed, the sea level dropped, but it was still warmer than today.
The neural network analysis of the book Where Troy Once Stood did not give me any data about St. Petersburg or the territory of modern Russia. I also quickly looked at the geographical maps from the book (a scan of the book was posted in this thread) - the eastern part of the Baltic Sea is not even mentioned there. There are several pages of text about Scandinavia - I did not find anything else. I would be glad to receive any help, since the book is written in English and I have to translate the text using Google translate/Google Lens.Well, if you haven’t read the book, then maybe you shouldn’t be so convinced that we only have the C’s words.
This is a good lead. Let the Finns forgive me, I did not think about them at all.Also search for "homer illiad in finland" for more references...