The excerpts you posted above Benjamin, reminded me about the video Keith shared recently in our Reading workshop for Darkness over Tibet. It’s a fascinating video on the ties between underground cities in Tibet & Antarctica, & how information about this got to a Soviet spy & then (possibly) the Nazis too. It is in English, made by a Russian lady who had dug into this subject a fair bit. I think she has some other videos on the topic as well (I haven’t watched those yet).
From Tibet to Antarctica: Betrayal, Soviet spies & Nazi Secrets (video ~30 minutes)
From Tibet to Antarctica: Betrayal, Soviet spies & Nazi Secrets (video ~30 minutes)