In America, there are old missile silos, refurbished for human habitation. I'm wondering, assuming ideal conditions, no earthquakes near the silos, nothing breaking into it, the door being sealed shut, how long would one of these missile silos last, just the interior itself, not any of the furnishings.
we would all be long gone before your silo crumbles
The silos themselves? Until the sun expanded, or a meteor fell on them. Or did you mean someone surviving in them?
A thousand years at least baring a major earthquake or a volcanic event hitting them.
