Toward Ecosophy

I've seen discussion on this list fairly often about these ancient civilizations--Hyperborean, Atlantean, and so forth, and of course enjoyed exploring them through your Weird of Hali series, JMG! As well as other fiction writers, including Tolkien. And I know most or all of them were mentioned by the ancient Greek philosophers and geographers. But in terms of a more serious and deeper understanding of them, where would I go? Theosophy? At the present time I don't know how seriously to take these ideas, but would like to learn more.

Thanks for any help!

Winifred