Founded in the 1770s by Richard Arkwright, the Cromford Mill was the first modern factory, producing cotton on automated machines powered by a series of waterwheels along the River Derwent. This prototype inspired a succession of mills, ushering in the industrial age. In addition to 90-minute audio-guide tours, there are weekly one-hour guided tours. It's 1 mile south of Matlock Bath (a 20-minute walk), or you can take the train one stop to Cromford (£2.50, five minutes, hourly).