I discovered a Sumatra or something natural wonder, which seems to span a lot of tiles (basically a bunch of forest tiles, that don't say anything at all when you hover over them) but when you zoom out to the point where the map shows geographical borders or something it says sumatra.

What does this wonder do? There's no feedback from the game. Does it give any bonuses, how does it work? It even spans multiple regions (like 4 or so).

As of the beta, nothing special. Besides being a named mountain range, forest, or river that shows up on the map.