Constructed before 2000 BC, this striking portal dolmen is one of Ireland's largest, measuring 4.5m by 3.3m. To reach it from Boyle's town centre, follow Patrick St west and then the R294 for 3km, until you pass under a railway arch. Keep going for another 400m and you'll see a small abandoned building on your right; stop the car here and climb up the hill and over the railway line (take care and shut the gates).