Tartarian Architecture in America

I read in the book of Enoch that Tartarus is a place where the fallen Angels were sent as punishment?
I'm hoping you can clarify this, is Tartarus , Tartaria?

I think Tartaria existed for a thousand years AD.
Giants lived among humans when you consider the monumental buildings built with very large doors. Maybe they were descended from Nephilim? We know Tartaria existed by structures and intact buildings still standing.
We we learn about Tartaria soon I reckon.
The thousand years were stolen or hidden from us. Here's a curious video from Jon Levi about the missing millenium. The San Francisco train station seen at the end of video was erected in the year 800 [forgot last 2 digits].