Charcoal was produced by colliers in the woods who slow burned logs to make charcoal. When brought to the Furnace, the charcoal was first put in the charcoal shed to make sure it was cool.This is a side view of the alleyway connecting the charcoal shed to the filler hole at the top of the furnace.This roofed alleyway connected the charcoal shed to the filler hole. Iron ore and limestone were held here, too.Filler hole at the top of the furnace where iron ore, charcoal, and limestone were added.