In 1815 James Kieran and his brother William built Philipstown Mills, approximately three miles from Dundalk at a cost of £30,000 – £40,000. These extensive watermills took advantage of the adjacent Castletown River. By 1818 the mills of Messrs. Callan and Kieran were dealing with 40,000 barrels of wheat a year. This large water-powered mill complex is now almost completely overgrown and ruinous. Impressive in scale. The remains of the waterwheel and millrace can also still be seen.