George Orwell

[...] at each stage of his imprisonment he had known, or seemed to know, whereabouts he was in the windowless building. Possibly there were slight differences in the air pressure. The cells where the guards had beaten him were below ground level. The room where he had been interrogated by O’Brien was high up near the roof. This place was many meters underground, as deep down as it was possible to go. 

It was bigger than most of the cells he had been in. But he hardly noticed his surroundings. All he noticed was that there were two small tables straight in front of him, each covered with green baize. One was only a meter or two from him, the other was further away, near the other. He was strapped upright in a chair, so tightly that he could move nothing, not even his head.  A sort of pad gripped his head from behind, forcing him to look straight in front of him.

For a moment he was done, then the door opened and O’Brien came in.