Skara Brae 3180 BCE–2500 BCE.Meanwhile the vikings=caves hunters or warriors? back then after all, history book let us know that our ancestors where savage man? the only way they talking about they knowledge is when they mentioned them as the myth or legends? so when you come across somethings like this you just tell yourself that it was built by Aliens?
after all the Neolithic some of them had elongated skulls? and that is somethings you see all over the world in museum? then you wondering where those guys with elongated skull went? why are human of today not been born anymore with elongated skull? i guess those elongated skull man disapeared may-be because there where homo=sexual? or they couldn't reproduced? or they where Aliens they went back to the sky? or human evolution is real as it get? that is why no children are born today with with elongated head?
there is somethings history book don't want you to know about our ancestors? in either way this was not just.