Following this recommendation, I went to the Southwell Workhouse on Saturday afternoon.
Gosh, what a fascinating, engrossing hour and a half! All the more remarkable, given that most of the time you are just looking at empty rooms, but the excellent audio tour (in my limited experience, second only to the one on Alcatraz island/prison in California) filled the rooms in one's mind.
To expand on what Sarah says, it was the first workhouse built specifically to separate women, men and children, and within those to separate the able-bodied and the infirm. There were even separate staircases so they would never meet.
It underlined to me what a place of last resort the workhouse was - life wasn't made so much unpleasant (though certainly by modern standards it was), as utterly un-enviable, with men breaking stones all day, women unpicking ropes, even repeatedly whitewashing the walls in an exercise of gross futility.
Almost most haunting of the lot was the top floor, apparently untouched since last used as a workhouse in the first half of the 20th century. Unless the audio-commentary hadn't mentioned it, I don't think I would have noticed the "shadows" on the floor - where the floor had been worn smooth by decades of inmates walking/standing between the beds.
The rooms are largely empty because they say there is no evidence as to what the furniture would have been like. One dormitory has some reproductions of (mid 20th century?) hospital beds, plus nightgowns and chamber pots, to give an idea of how they might have been laid out, and one room is kept as it would have been in the 1970s, when (parts of?) the building were used to house homeless families. In a way the 1970s bedsit was almost more claustrophobic than the 19th century recreation, as it feels more familiar.
I'd have liked to have known more about the building's history in the 20th century. The audio commentary was almost uniquely concentrated on the early to mid 19th century, and it would have been interesting to hear how the building was adapted (if it was) in the late 19th and early 20th centuries and how workhouse life differed then; and then how the building was used in the second half of the 20th century.
Definitely recommend a visit if you're within a 100 miles. It's nearer Newark, than Nottingham though. Southwell looked a lovely small town too, though unfortunately time was pressing too much for me to be able to explore it.