Stonehenge question and one other question

[Jimbo30]

I also built stonehenge that game, and it doubled to 16 culture after about 1500 years (it could have been 1000, I wasn't paying too much attention). One theory could be that another civ getting Calendar obsoletes it for the purpose of the culture output, but you don't lose the obelisks until you get Calendar yourself.

 

[Jeff1787]

I also built stonehenge that game, and it doubled to 16 culture after about 1500 years (it could have been 1000, I wasn't paying too much attention). One theory could be that another civ getting Calendar obsoletes it for the purpose of the culture output, but you don't lose the obelisks until you get Calendar yourself.

I don't see anything about wonders doubling their culture output when they become obsolete. Here is what Civilopedia says:

 

[Jimbo30]

Yeah the manual and civilopedia probably misses a lot of stuff out.

There's definitely some doubling effect for culture, I'm now getting 16 for the Oracle as well...