Towers are defensive buildings placed at intervals based on expansions along your castle wall. When the player first plays the game, they will automatically have four empty tower slots. As you progress in the game, you can unlock higher and higher level towers. The number and level of towers you have affects the amount of troops you can have stationed along your castle wall. The more troops you can have along your castle wall, the less likely it is that an attacker will make it past all three of your flanks and get a courtyard bonus. Towers have eight levels, each progressing in the number of troops you can station. Towers also give a very small amount of public order, defined as “protection” public order.
To have a certain level tower, you must have the corresponding level castle wall. For example, if you have unlocked level three towers, but you haven't upgraded your wall yet, you won't be able to build the level three towers. This is a trait towers share with castle gates.
The color and general style of each level of tower progress in the same way as The Keep.
The flag will stay the same style of four squares even if your flag only has two, also your symbol won't appear on it.
Since October 2022 update, it is possible to have more than 3500 unit limit on the castle wall.