Speaking of Underground mushroom farms

On the former site of a quarry, the farm is 50 meters underground has been operating since 1893. It sprawls throughout seven underground levels of stone rooms filled with mushrooms, which yield 100 tons of the tasty suckers per year, each one hand-picked. In fact, if you've ever had a pied bleu mushroom (blue foot mushroom), there's a good chance it came from this cave—40 percent of the world's blue foots are grown here. Link

Orcs would love this place.