Durham Mill and Furnace is a historic grist mill located in Durham Township, Bucks County, Pennsylvania. The mill was built in 1820, on the foundations of Durham Furnace. The furnace was built in 1727 and remained in operation for 70 years. It produced pig and bar iron and during the American Revolution cannons, ballshot, and other military equipment. One of its managers was Col. George Taylor (c. 1716–1781), a signer of the Declaration of Independence. The mill building is a three-story, stone structure with the overshot wheel located inside. Attached to it is a large, brick gambrel roofed warehouse added in 1912. At that time, the post office opened at the mill, the second oldest post office in the United States; the Durham Post Office was founded in 1723. The mill was owned by Congressman Reuben Knecht Bachman (1834–1911) in the late-19th and early-20th century. The mill remained in commercial operation until 1967.