TPI is an Exploration of Myths, Legends, UFOs, Entities and all sorts of other Anomalies & Mysteries in the Multiverse of Sci-Fi & Popular Entertainment.
https://www.youtube.com/watch?v=NxpZ_g3sMCw Ancient Aliens
An ALASKAN Pyramid that's Underground & MASSIVE https://www.youtube.com/watch?v=6UI_oG91lcI
Fascinating stories and conjecture, but very tough to prove.