National Wonder. Can only be built once in your empire. To unlock: Requires that you are at War with other Civilizations. Must be built adjacent to an Encampment district.
+1 Military policy slot. Provides the same defensive bonuses as the Fort improvement. Grant Walls and Medieval Walls in this City. Promoting a unit does not end that unit's turn. +4 Combat Strength for all military units in your territory. All buildings in Encampment districts provide +2 Production and +2 Culture. +100% Encampment district Production adjacency bonuses. Military Engineers gets +1 Movement and +1 build charge.
+2 Tourism
+1 extra per Era that you've advanced past this Wonder's era