Here is a RL Fallout Vault from 8th to 7th centuries BCE in Turkey; later taken over by early Xtians around 500 - 1,000 CE. One of the cities could hold up to 35,000 people plus food storage, live animal storage, and wine making equipment. This city is Derinkuyu and it connects through underground passages to around 200 other cities.

The entries could be sealed from the inside by rolling huge stones across the openings

that's pretty cool actually! I have all the fallout games, from the originals to the xbox overhead view game to the fallout 3/new vegas. love em!

Been to a few of those places. Impressive constructions, especially if you consider they were dug out by hand.

er guys, did you notice the dates the thread was started?