world_lower.png
---------------

    Sea
    Grass
    Sand
    Dirt
    Mountains
    Snow
    Snowed Mountains
    Forest
    Roads


world_upper.png
---------------

ok  Bridges
ok  Trees
ok  Tower
ok  Well
ok  Rock
ok  Log Pile
ok  Barrel
ok  Volcano
ok  Cities
    Castle


city_lower.png
--------------

ok  Streets
ok  Sidewalks
ok  House walls (concrete)
ok  House walls (wood)
ok  Building (residential)
    Building (commercial, shopping center?)
    Stores
    Church
    Park
    Water
    Walls
    School


city_upper.png
--------------

ok  Flowers
    Metal fence
    Log fence
ok  Roof (tiles)
    Doors
    Windows
    Canopies
    Bike racks
    Transit signs
    Bus stops
    Benches
ok  Trees
ok  Rock
