Workers brought limestone rock from the quarry to these kilns for burning. The raw rock was loaded into the kiln from the top, alternating with layers of coke, a hot-burning residue of coal. The rock was heated in the kilns to prepare it for later pulverizing. Workers removed the cooled limestone, called quicklime, from a metal collection basket at the base of the kiln and dumped it into a horse-drawn cart. It was then carted to the grinder/slaker shed on the east side of the kilns for processing into smaller sizes or powder. During World War Two, German prisoners of war were bused to Fountain Rock to help provide labor.