The Stronghold is a the primary structure of your Base. Its level determines the level to which you may level up all other buildings.
It may be upgraded to a maximum of level 20 and gains additional space in which to build, along with the corresponding possible buildings to fill those spaces, at the following levels:
Stronghold
| Level | New Buildings |
|---|---|
| 3, 8, & 15 | Farm, Mine, Food Storage, Forge |
| 5, 11, & 20 | Farm, Iron Storage, House, Training Camp |