Today's teaching material is on workplaces and prepositions. I work in a hospital, on a farm etc. In addition to a long and useful list of examples, the authors have added in a mine. This is good-to-know stuff but I promise that not ONE of my students will know what a mine is. This is Hong Kong...if you ask someone where gold comes from they'll say "the shop".
I'm simply going to claim that a mine is where Prada handbags come from.