York, PA
The York, PA plant, founded in 1973, is the largest Harley‑Davidson manufacturing site and spans more than 230 acres with over 1.5 million square feet of covered space. Visitors can observe the full production line—from machining and polishing to welding, painting, and final roll‑testing—while learning about the history and operations of the facility. The tour also offers family‑friendly areas, including a Kids’ Rally zone and the chance to sit on a motorcycle that has just completed production.
http://www.harley-davidson.com/en_US/Content/Pages/Factory_Tours/factory_tours.html