Headford, some 28 km north of Galway, is the popular angling centre for the eastern shore of Lough Corrib, and Greenfields, some 6.5 km west of the town, is its boating harbour. The town is situated next to the Black River (noted also for its trout angling) which is the county boundary with Mayo. Headford is also the centre of an area rich in archaeological monuments, ranging from prehistoric burial cairns, Iron Age stone enclosures, early Norman and later castles, to a bewildering array of monastic sites. These include nearby Ross Errilly Friary, founded in 1351, which has been described as the best preserved monastic ruin in Ireland. Today, the modern cattle mart, although replacing the fairs and markets once held in the town's two squares, ensures the local popularity of this North Galway town.