"Stronger towers made of stone. Units can be placed in these towers to be protected and extends their watch and attack range."
Stone Towers are the upgrade of Wood Towers.
Towers are a supplemental defensive construction that temporarily allows units to act much like a turret. Each tower can hold up to 4 units constructed in a Soldier's center. Units in the tower cannot move, but can still fire and do so with enhanced range on their attacks. Units can be ordered to enter or unload from a tower and may exit from the tower on any unblocked side.
If a tower is destroyed, all units in it are deposited in the tile where it was destroyed.
Stone Towers extend the watch and attack range of units inside by 4.