Miles and miles of tunnels and chambers exist underneath the pyramids in Egypt, so deep that they still have not been fully explored. Where do they go? In the Egyptian Book of the Dead, there are numerous references to opulent, subterranean worlds, accessed through these tunnels, and the tunnels under Tibet are deemed to lead directly to Shambala/Shangri La, a Vedic city in the hollow earth.Pyramids
Solid rock is the ideal material to build space crafts. One would need many meters of wall to keep the radiation out. It's always been a mystery how the stones used for ancient buildings fit on top of another like a glove.
The primates of the 21 century like to think of their ancestors as if their the primate party. But given their astrological knowledge one should know better than that. People probably OD'ed on the entertainments. Yeah, I think we have probable cause.
Anyway, I would build such craft just like the pyramids look. They would have to be solid enough to resonate and to "generate" gravity (shield off the ZPE)
Habitats on "Alien" planets are of course constructed below ground. Terraforming and adapting might take many revolutions.
So the pyramid drilled it self deep into the ground from where we tunneled ourselves a way into Terra or it is an unfinished ship build to leave the planet. Given the size of the door, the astrological knowledge and the tunnel system it is clearly a ship. It's shape may have additional purposes.
As above so below. As outside, so within.
If you still want to believe in linear development you might want to consider drawing the line downwards rather then pretending there is progress. Or you can chose not to and serve as the prove of it.