How do I find the Fountain of Youth?

I am trying to get the Dr. Heidegger's Experiment achievement but I have no idea how to find the Fountain of Youth. Is it on a specific type of map or something?



Many thanks.

It's a Natural Wonder, but very rarely shows up in games - I saw it yesterday for the first time in BNW, and I may not even have seen it during G&K. You may have more luck finding it on the scenario that introduced it, the original Conquest of the New World (although the achievement will trigger in the main game as well).

Just keep playing, and you'll stumble upon it one of these days, only to realize you've been playing on offline mode.

Play the "Conquest of the New World" scenario