Season 2 of the "Secret Nazi" Series: Experts dissect and reveal the markup, technical designs and true purposes of some of Nazi Germany's most unique relics.

"Secret Nazi Bases" - a multi-episode television series about hidden structures and secret plots of the Nazis aired on the Science Channel in August-September of 2021 and on several outlets around the world, including UK TV, Discovery Channel in Europe.
https://www.sciencechannel.com/show/secret-nazi-ruins-science
https://gobuttonmedia.com/factual/secret-nazi-bases/
https://www.imdb.com/title/tt10187646/fullcredits/?ref_=tt_ov_st_sm