Just remembered...

Can anyone explain to me the arrangement at Oxford, up until at least the early 20th century, of students living on "staircases"? What does or did that look like? How were the halls at the old colleges arranged?

I understand the same system prevailed at Harvard in the 18th century and I can't find any pictures or floor-plans or anything (though I've come across some really interesting stuff about riots in the Harvard dining-hall because the food was so bad).