Take a short trip out of Letterkenny for a first-hand look at the technology that powered the Industrial Revolution. The oldest surviving building at Newmills is 400 years old and there have been mills at Newmills since the early nineteenth century. In Victorian times a flax mill lay at the core of the complex, providing crucial supplies to the linen industry, the backbone of Ulster’s economy at the time. A corn mill ground barley, oats and imported maize.