Recently Leoreth split mounted units into light and heavy cavalries and introduced a new promotion that gives combat bonus on open terrains, which in my opinion introduced a good timing for discussion on modifying the existing world map, plot types and terrains. I've always wanted to make suggestions on improving the world map to make it more historically and geographically correct. But changing the map means changing a lot of files, so to avoid the unnecessary work and the unwillingness to change caused by it let's first discuss on improving the plot types and terrains system. Here are my suggestions: New plot type: Mountain. The mountain plot type is almost indentical to the Hill plot type, but impassable to most military units and cannot be settled. Mountains can be worked on. (Improvements on mountains need a way to be destroyed though.) The good thing about the introduction of Mountain is that we can replace certain Peaks and Hills with Mountains to create strategic choke points, while not having to worry about too many Peaks destroying city yields. Rename the plot type Grassland to Flatland. New plot type: Plateau. The Plateau plot type functions mostly like Flatland. It's conceptually more pleasing and gives mounted units historically and geographically correct battle fields. Suggestions on its other functions are welcome. I'm thinking about a small plateau-to-flatland attack bonus and/or flatland-to-plateau attack malus. Also an extra cost for entering plateau from flatland is in order. Many Hills and Grasslands (plot type, not terrain) on current DoC map should be replaced by Plateaus.