To build a Wall, simply click on the wall under city tab, and build/upgrade as you would any other building. Note that you no longer need a level 2 Quarry.
Durability is health of the wall.
|1||Provides 100,000 Durability and 1000 Defensive Unit Spaces|
|2||Provides 300,000 Durability and 3000 Defensive Unit Spaces|
|3||Provides 600,000 Durability and 6,000 Defensive Unit Spaces|
|4||Provides 1,000,000 Durability and 10,000 Defensive Unit Spaces|
|5||Provides 1,500,000 Durability and 15,000 Defensive Unit Spaces|
|6||Provides 2,100,000 Durability and 21,000 Defensive Unit Spaces|
|7||Provides 2,800,000 Durability and 28,000 Defensive Unit Spaces|
|8||Provides 3,600,000 Durability and 36,000 Defensive Unit Spaces|
|9||Provides 4,500,000 Durability and 45,000 Defensive Unit Spaces|
|10||Provides 5,500,000 Durability and 55,000 Defensive Unit Spaces|
|11||Provides 6,600,000 Durability and 66,000 Defensive Unit Spaces|
|12||Provides 7,800,000 Durability and 78,000 Defensive Unit Spaces|