Relic from early huts

[Myth and Legend]

Apart from getting a free settler, I think this is the best thing you can get. 4 faith per turn since 3600 bc is amazing, not to mention the tourism.

 

[Tavenier]

To me, the relic even beats the settler, sice the settler isn't that expensive to make anymore. Especially with some civics.
I got one early on in a Greece game! Talk about culture overload!