I used to think the same until read a story about a orifice type device being discovered in the Ziggurat of Ur when first excavated. David Wilcock(not popular on this forum but I like him) said some of his 10 whistleblowers claimed it also existed.
That's all fun and good rumor until I realized what material in the form of a ring would make it work. Then it was like aha! What material has a natural spacewarp around it? Can ya guess?
Dan Burisch claims that he witnessed up to a minimum of 50 different man made stargate portals around the earth. All created from instructions carved on ceramic cylinders discovered buried in the middle east. I think they have to be located upon natural vortex points to work. I believe he did mention there are natural wormholes located across the planet and they utilize them.
So would not only plans but in addition actual technology found?
My guess is the material that has a natural spacewarp around it must be Ormus ..
Im only joking actually, but my guess would be Germanium as allegedly it contains those pesky time-travelling particles, Tachyons ..