This Hiroshima map for Age of Steam is themed around the area's association with the color red: the Torii gate at Itsukushima Shrine, Momiji Manju (a maple-shaped cake), and the local baseball team. As the game progresses, many cities will change to red.
All new city tiles (other than the red one) begin on the board, covering red cities, and some of the non-red cubes are removed from the game. When you would add a new city, instead, move one of the new cities that is on top of a red city to a town hex. Delivered red cubes are worth additional victory points at the end of the game.
The game also features special "enhanced" actions. Once per game, a player may use an upgraded version of the action they choose from the auction. Additionally, once a specific enhancement has been chosen by a player, the other players may not use that one.