This site wasn't entirely indoors, but indoors enough to keep us relatively dry. This is the Bonawe iron furnace, which produced iron between the 1750s and the 1870s. The site of the furnace was based on the availability of trees for charcoal and, at its peak, over 600 tree cutters and charcoal burners worked here. This photo shows some of the charcoal sheds, where charcoal was loaded in from second story windows at the back. The iron made here with either cast into pigs, and shipped back to England, or made into cannonballs.