For story reasons I'd like to have a mine which exploited part was turned in to a nuclear shelter, for the city built above. Later, the nuclear shelter was utilized effectively as an district of city involving hospitals, prison, gov offices, swimming pools, museums, storage facilities, social housing, etc.
1) Realistic or not specially? I failed to google any mines used as nuclear shelter, so I'm a bit worried about this part.
2) What ore should be realistically mined? For story reasons I need something mined in huge quantities, but not fossil fuels. I thought about some good quantity iron ore like magnetite. Reasonable? (or would it cause any troubles)
3) How such district should look like if was designed in such mining tunels. I mean assuming that there was done as little extra work as possible? How big should be realisting tunels left after mining ore?
4) Any visible challenges that would make the project not worthy, and convince local gov, that if it needs proper shelter it should rather build it from scratch?