There are many mysteries in the world today, I do feel sorry for all the ancient sites that have been termed Unesco World Heritage Sites, i think i covered that in a previous comment.
I think one of the reasons for a lack of knowledge on many of these sites is that for some reason some group does not want the average person to know. he who controls the past controls the future. We have only been thinking smart modern man for this many years, therefore everything that does not fit the narrative is a lie.
Maybe the door ways were so big because men were giants back then. Or because they rode creatures that were giants. Who knows, maybe one day we will learn the truth, but it is going to be a difficult thing to prove.
You did mention that before yes, and for the "some group" I tend to call them "those you are not allowed to challenge or comment about" if you know what I mean? you know who runs the show, when you know who you are not allowed to criticize. And yes for sure were are being told half truths, that's why I keep digging, caring is sharing, thanks for a superb comment.