Can't build Louvre

So I was playing as France and ahead of everyone scientifically but could not build the Louvre in any of my cities. I didn't see any prereqs in the description and like 25 turns later Ethiopia built it. WTF?

Did I miss something very obvious here?

Yes, you missed the fact that you need to open the "Exploration" policy tree as a prerequisite.

You now need the opener of Exploration I beleive. That or Asteics, at any rate read the opener of all the SP's and you can find it.

Nearly got done by this - in fact it was just by chance that I spotted a post on here that mentioned the Exploration opener that I just about managed to open the tree in time!

Would've been hilarious to have missed it after beelining for the tech for so long

So much new stuff to learn!