The Acropolis can secure your Units and Resources in the event of an attack. Units inside the Acropolis will be protected in the event of a Raid or Siege - but also unable to participate in your City's defense.
While there is no limit to the number and type of Units that can be secured in the Acropolis, the amount of Resources that are automatically stored in your Acropolis is determined by its upgrade level.
The Acropolis has 2 interface tabs:
1. "Info" - This tab displays the amount of your Resources that will be protected in your Acropolis at its current upgrade level. You will also see the Resources required to upgrade it.
2. "Units in Acropolis" - This tab allows you to view the Units you currently have in your Acropolis, add more, or return them to active duty.
All secured Units are displayed at the War Council (under the "City" tab).
It takes less than one minute to send Units to the Acropolis. If your City has been successfully spied upon, your hidden army will not be listed in the enemy's Report.
You can upgrade this building by using Upgrade Sketches, which can be acquired from the Market.