Age of Sparta
20 Achievements
200
PC
Mobile
Fortified
Build 2 defensive structures
10
How to unlock the Fortified achievement in Age of Sparta - Definitive Guide
Defensive structures unlock at level 20 (buyable with gems). If you want to avoid spending your gems on the two structures needed for this achievement, at level 25 you unlock the fortification workshop which will build the structures for coins instead. After your second structure is built, the achievement will unlock.