In the first image you can see there's a village over oil. So I decided to test the behaviour of "Improve Resources" diplomacy option with Belgrade (second image). The result is an invisible Offshore Platform on the tile! (third image). Of course it shouldn't happen because:
But the oddities continue. Going back to the CS Diplomacy Screen I see that I have the option to "Improve Resources" again. I pay another time and the result is an Oil Well (fourth image). I've discovered I can cycle between the invisible Offshore Platform and the Oil Well as the "Improve Resources" remains active in the CS Diplomacy Screen.
The following turn a Belgrade worker begins to build a Village again (fith image) as, I guess, Belgrade has no knowledge of Biology either and doesn't see the Oil Well.
- It's a land tile.
- I haven't discovered Biology yet, as you can see in the image.
But the oddities continue. Going back to the CS Diplomacy Screen I see that I have the option to "Improve Resources" again. I pay another time and the result is an Oil Well (fourth image). I've discovered I can cycle between the invisible Offshore Platform and the Oil Well as the "Improve Resources" remains active in the CS Diplomacy Screen.
The following turn a Belgrade worker begins to build a Village again (fith image) as, I guess, Belgrade has no knowledge of Biology either and doesn't see the Oil Well.