Ark-City - a utopia in middle of wasteland. Before civilization fell, a massive project was started to make cities to save at least some of population and civilization. Now it stands, among rusting ruins of metropolis, its dark ancestry. Outside of this city may be survivors, trying to survive wasteland, but citizens of Ark long for nothing, they live in near utopia...

Important features:
Hydrophonic towers produce food for citizens. Food is mostly plants but some meat is produced, both artifical and natural.
Water purification plant recycles wastewater as well as serves well to deep water sources.
High-speed railway connects to other Ark-Cities.
Tower based shield system purifies air from the worst contamination.
Old city district allows citizens to connect with old culture.
Industry sector allows city to remain mostly self sufficent, and if there is lack of something trade with other Ark-Cities and outside will solve this issue.