Defensive structure

Defensive Structures are a type of building available in every Age of Empires game. Rather than be used to train Units or research Technologies, they are used to defend your civilisation from attacks, or warn it of attacks.

Age of Empires
All defensive structures reasearched and upgraded from Granary:

Towers found in the campaign and the scenario editor:
 * 1) Watch Tower
 * 2) Sentry Tower
 * 3) Guard Tower
 * 4) Ballista Tower
 * 5) Small Wall
 * 6) Medium Wall
 * 7) Fortification
 * 1) Zenobia's Tower
 * 2) Mirror Tower

Age of Empires II
All defensive structures researched and upgraded from University


 * 1) Outpost
 * 2) Watch Tower
 * 3) Guard Tower
 * 4) Keep
 * 5) Bombard Tower
 * 6) Palisade Wall
 * 7) Stone Wall
 * 8) Fortified Wall
 * 9) Gate
 * 10) Sea Wall
 * 11) Sea Gate

Age of Empires III

 * 1) Outpost
 * 2) Fort
 * 3) Trading Post (With Home City Card)
 * 4) Town Center