Constructed in 1930, the Old Mill had originally been of service at Hermitage between Rome and Calhoun, Georgia. Henry Ford had the hub moved to Berry where the wheel was rebuilt. The wooden overshot waterwheel is considered one of the largest in the world at 42 feet in diameter. Water is piped directly from Berry's reservoir lake to the wheel. Once primed, the force of gravity is strong enough to push the water up the stone column, and over the wheel, causing it to turn.