Fortifications
Better fortifications and higher walls around town, also increases the max garrison limit since it provides more space for the resident troops.
Levels
- Level 1: +60 bonus to garrison capacity +50 increase to prison capacity
- Level 2 (6,000): +90 bonus to garrison capacity +75 increase to prison capacity
- Level 3 (12,000): +120 bonus to garrison capacity +100 increase to prison capacity