I'm still new in Civilization 4 and had a lot of questions about playing the game. I'm finding the game to be insanely complicated so please keep that in mind while giving your answer. If you use too much game jargon I won't understand. Thanks for your help in advance.
Question: If I double-click on my starting city I come accross a map which shows some white circles. I think those circles are choosing what tiles are being used to calculate my per turn balances. But why aren't all tiles in my territory showing up? What do I do to have more options for the circles?