Cities vary depending on climate. Most cities are surrounded by walls, using natural barriers as much as possible for defense, such as rivers, cliffsides, or hills.
Depending on the level of expansion, advanced masonry, wood, stone blocks, and simple leather huts are built, always starting from what is easily available. Structures common to many settlements are simple guard towers, meeting halls, inns, housing for families, and aqueducts. Eventually, all human holdings grow to become strongholds in their lands.