What does Heavy Fortifications do in AoE3?

Gives: Sentry Tower; Gives: Guard Tower; Gives: City Walls; Gives: Heavy Fixed Guns. The game says: "Grants free improvements that increase the combat ability of Walls, Outposts, Blockhouses, Forts, War Huts, and Nobles' Huts."

Home City card

Heavy Fortifications

Heavy Fortifications (tech ID DEHCHeavyFortificationsAfrican) is a Home City card in AoE3: Definitive Edition 100.19.18309, in the decks of 2 civilizations, sent from the Industrial Age. Effect: Gives: Sentry Tower; Gives: Guard Tower; Gives: City Walls; Gives: Heavy Fixed Guns.

Quick answers (3)

Which civilizations have the Heavy Fortifications card?: Ethiopians and Hausa.
What does Heavy Fortifications do in AoE3?: Gives: Sentry Tower; Gives: Guard Tower; Gives: City Walls; Gives: Heavy Fixed Guns. The game says: "Grants free improvements that increase the combat ability of Walls, Outposts, Blockhouses, Forts, War Huts, and Nobles' Huts."
What is the tech ID of Heavy Fortifications?: DEHCHeavyFortificationsAfrican.

Grants free improvements that increase the combat ability of Walls, Outposts, Blockhouses, Forts, War Huts, and Nobles' Huts.

What it does

Gives: Sentry Tower
Gives: Guard Tower
Gives: City Walls
Gives: Heavy Fixed Guns

Cost: 1250
Sent from: IV
Times it can be sent: 1
Game ID: DEHCHeavyFortificationsAfrican

In these decks

EthiopiansIV×1

HausaIV×1

Source: techtreey.xml and the Home City files, AoE3: DE 100.19.18309 (build 25040513).