Have any human societies ever lived underground?

[Chainfire]

11. Living in high-density city centers is not a hell of a lot different than living underground.

Given the choice of a high-rise or a cave, I might take the cave; solve the ventilation issue and I would be good to go. But, then again, I am a troglodyte as well as a semi-hermit, so it is all copesetic to me. A lot of people lived in cliff dwellings from time to time, and that is just a horizontal version of living in caves. 150 feet of the World Trade Center (5 floors) is below ground and that is typical of a high rise.

It would get awfully stuffy in the sketch shown above, especially since all light would be by open flame. When people farted it would never dissipate. Walk into a room and it could bring tears to your eyes. (Yea, that was the sausage and cabbage joe ate back in Jan.) Perhaps the underground civilizations also had strict dietary laws. If nothing else, we are adaptable.

If we don't destroy ourselves first, underground living may be the ticket. Utilize the open-air spaces for growing food and collecting energy and tunnel like moles.