That doesn't explain how they considered everything belonged to them when nobody lived forever.At 930 years Adam would have been very wise compared to a person who lives 90 years today. I'm also going to assume that things went downhill from Adam rather than Noah knowing a lot more than Adam did.
You can trace the history of the megaliths.If Gaza is used as a starting point and no date applied you can still date things as newer or older. The progression back it time would see Turkey having older sites and the Ukraine even older sites and then it moves west through Russia until you get to China and that is where the oldest sites are found and the least is known about them.
If you care to speculate a bit it can be promoted that 200M ago the ocean basins we have today would be gone but the water would still be there and it would have been pushed up on the land and the earth would have been one sea with no megaliths and as the water drained off the land the megaliths started to appear. I would need to get the elevations of all of them as see if that fits in with which is oldest and which is the most recent. Gaza is close to sea level so it would have been one of the latest one while the ones in the mountains of South America would have had them being at sea level and moving all the big stones would have been by floating them across valleys that were full of water rather than dragging them down one mountain and across a valley and up another mountain. a raft would have been much easier and much faster.
No comment as I would see it as a cure for the biggest fuktards on the planet today.
		
		
	 
 It is simply not possible assign an age to much of anything from our remote past past or even stuff from a hundred years ago because there are no stable fixed points of reference no reliable decay rates for anything, star charts yes but which cycle?
ICS - Chart/Time Scale  The International Chronostratigraphic Chart [above] structures 4,600  million years of Stratigraphy into a consensus “hymn sheet” for  mainstream geologists.
 However, the down side to this mainstream chronology is that  mainstream Geologists have to align their observations with the  predefined “pigeon holes” in the mainstream chronology. 
 Unfortunately, chronology is not a precise science [to put it nicely]  and inevitably different Geologists will assign different chronologies  to a particular stratigraphy.
 Therefore, to preserve the integrity of the mainstream “hymn sheet”  mainstream Geology uses all of the “dark arts” that have been pioneered  by post-normal science:
 1) Harmonise conflicting chronologies [“science by committee”].
2) Rationalise preposterous chronologies [“science by computer model”].
3) Create “virtual reality” chronologies [“science by data manipulation”].
4) Manufacture the preordained chronologies “to order” [“science by funding”].
5) Exclude controversial chronologies from the official record [“science by peer review”].
6) Quietly forget about any offending chronologies [“science by omission”].
 The process of “consensus management” can be tracked via the annual  editions of the “International Chronostratigraphic Chart” [above] and by  reviewing the “Global Chronostratigraphical Correlation Table for the  last 2.7 million years” [below].
 
	
 Global Chronostratigraphical Correlation Table for the last 2.7 million years
International Commission on Stratigraphy
ICS - Chart/Time Scale 
  The “Antarctic Isotope Record” section of the “Global  Chronostratigraphical Correlation Table” provides a wonderful example of  mainstream “consensus management”. 
 
	
 
  The Vostok Research Station is at an altitude of 3,488 meters above  sea level and the Vostok ice cores, to a depth of 3,623 metres, have a  chronology dating back 420,000 years. 
  In the 1970s the Soviet Union drilled a set of cores 500–952 m deep.
These have been used to study the oxygen isotope composition of the ice,  which showed that ice of the last glacial period was present below  about 400 m depth. 
 Then three more holes were drilled: 
 in 1984, Hole 3G reached a final depth of 2202 m
← The Inflating Earth: 4 – Gravity Mathematical Alchemy → Chronology: 1 – Ice Cores Posted on June 18, 2013
However, whilst the Antarctic EPICA Dome C chronology covers more  than 800,000 years the North Greenland Ice Core Project chronology only  covers a meagre 140,000 years.
 This farcical “science” of ice core chronology is based upon some  very strange ice flow dynamics because in the Northern Hemisphere ice  sheets over 3 kilometres thick only manage to compress [on average]  45.38 years into a single metre of ice core whilst the Southern  Hemisphere ice sheets manage to compress [on average] 245.16 years into a  single metre of ice core. 
 Apparently, southern ice sheets manage to squeeze in 540 percent more years into a metre of ice!