The R115 road is a regional road in counties Dublin and Wicklow in Ireland. It follows the Military Road (Irish: An Bóthar Míleata) for its entire length. The R115 is 40.5 km (25.2 mi) long; the full length of the Military Road (Rathfarnham to Aghavannagh) is 57.9 km (36.0 mi). It was one of the first purpose-built roads in Ireland, excepting turnpikes. Four barracks were built along the way at Glencree, Laragh, Glenmalure, and Aghavannagh. The engineer in charge was Alexander Taylor (b. 1746), who was responsible for many other roads in the country, including some turnpike roads (toll roads).