salt mines
One's job or daily work, especially when it is very hard or unpleasant. (Workers in salt mines were often slaves and prisoners.) Sometimes used humorously. The commute to the salt mines each morning has got to be one of the most depressing parts of my day. Well, that was a wonderful trip, but it's back to the salt mines tomorrow!
salt mines
Humorous characterization of one's job. Salt deposits are often found underground, and even in the last century prisoners were condemned to long years or lifetimes of excavating the substance. Little wonder that it became a metaphor for hard or otherwise unpleasant work, as in, as you return to the office after lunch, “Well, it's back to the salt mines.”