City of Iron: Clockwork Fortress and Cave Market Promo
Clockwork Fortress and Cave Market cards are a promo for City of Iron (1st edition).
These cards are added to the buildings deck. The Cave Market adds one coin to your income for each different type of good you own. The Clockwork Fortress allows you to change the order of your citizen and military decks each time you refresh a deck.
For more information, visit the BGG listing.