Originally, the Stronghold had 6 minimum range, 3 area damage, and capped its bonus damage at 50 units. With update 6159, it has no minimum range, 1.5 area damage, and caps its bonus damage at 25 units.
Originally, the Sacsayhuaman card gave the Stronghold +3 range and +50% hit points. With update 6159, it gives +1 area damage and +50% hit points.
With Update 9476. Stronghold: Corrected the radius of the "range ring" to properly reflect the building's range.
With Update 9476. Thunderbolts of Illapa (Stronghold): Moved from the Fortress to the Industrial Age.