Notes

◾Futuristic Skyscraper All-In-One: Best for any biome, just need place for pillars. Preferred for creative. A massive, costing... and perhaps ugly structure. If you want your inhabitants to feel like being sheltered or compressed together, this is the best solution. It's designed as a heavy skyscraper with many districts and zone scattered trough it. You can build it of any form - Just remember to be futuristic and realistic. It can be a real maze with multiple layers and floating parts.. or a simple big prism with many corridors. For extra effect, try to make it feel as if a nuclear disaster fell on the world and the ground-level towns are infected by zombies and that the toxic air obliterated the open-air districts. Your "roads" may be accessible by walking, and may be built with glass cover. They can pass through plazas like some kind of highroads. They can give rapid access to certain parts of the skyscraper because it is divided by many areas. You can have some layers, some "zones" restrictions and much more. Remember to have solid, hard pillars made with obsidian or iron blocks to sustain your maze of hallways protuberances. The pieces may be linked together by growing onto sides of roads. Here are examples of layers or "zones" :
◾Level 0 to 4 = Death zone. Only access to the outside. Everything, except authorized military patrols with radiation suits,(Armor of your choice.) will be flagged an infected entity and will be killed.
◾Levels 5 to 22 = Military zones. Access restricted for armed soldiers or highly authorized federal agents, scientists, test subjects or politicians.
◾Levels 23 to 64 = Heavy Industrial zones. Big factories with high polluting. Laboratories. Sewers. Redstone power lines.
◾Levels 65 to 80 = Average to poor zones. Homes for the less fortunate apocalypse survivors. Basic services.
◾Levels 80 to 85 = Luxury zones. Lots of homes for rich people who can afford to live far away from the apocalypse. In order to build this high, you must be on classic flat and have the bottom two levels be built into the ground, OR you can mod your game to let you build higher.
Think about a futuristic city built in one huge building with floating parts, all of these linked together. Try combining with Ruins or Steam punk city type for best effect. Note* this doesn't HAVE to have 85 levels, this is just an example