Age Of Empires II: Age of Kings Easter Egg - A Crop Circle

1. Load the first scenario of the William Wallace Learning Campaign: Marching and Fighting.
2. Bring up the chat window and enter the cheat code "marco" to reveal the entire map
3. When the whole map is revealed, look at the Mini-map.(the diamond-shaped map on the lower right corner of the screen) Near the east end of the game map, you'll see a marking of two letters: "ES". It looks as if some alien representative from Ensemble Studios landed on this map from a spacecraft.
4. To take a closer look at this "crop circle", remove the fog of war by repeating step 2 and typing "polo" instead.