Need help with game name.

To the best that my memory can remember.

First, I remember the name of this game being "Castles".

It was a sort of multi layer or hello type game. At layer one you placed flags, flags changed into something else, and at the third level it changed into a castle. It was a turn based game, and would allow for two players or player vs AI.

This game had a fantastic AI that learned from you, making you have to constantly update your strategy.

The correct name, pics, and links would be most appreciated.