Parts of rural France have some really old bits of industry lying around. One of the more common types of surviving building still in use today are the old mills that were used to create both flour and oil.
Of course, not all the mills that once dotted the landscape have survived intact. Many, whilst still technically classed as mills, no longer operate as such, having been turned into guest houses, or restaurants, or terribly good looking private accommodation. A water wheel stuck on the outside of your house being the ultimate water feature for the discerning property buyer.