Library: a wooden single-story or double-story hall, guided by cobblestone stairs, with a large number of bookshelves, wooden railings, ladders, chandeliers and cobwebs. Libraries vary in size. A small library usually contains bookshelves, wooden floors and a box.

This is an abandoned mine. Very common underground. There are treasure boxes. Wash the cobwebs with water. Note that spiders are poisonous spiders. Abandoned mines are of little value except rails and cobwebs.

Your RP is very good ~ this is an automatic artificial mine hole in my world, and this is where you can mine.