Occupied continuously from the Neolithic period to late medieval times, this lovely lake’s shores hold an unusual preponderance of ancient sites. Most of the sights are well signposted on the R512, the drive that skirts around the lake’s edge. Archaeologists have uncovered foundations of a small farmstead built around the year 900, a lake island dwelling built between 500 and 1000, a wedge-shaped tomb that was a communal grave around 2,500 B.C., and the extraordinary Grange Stone Circle, a 4,000-year-old site with 113 upright stones forming the largest prehistoric stone circle in Ireland. An interesting Heritage Centre helps put it all into context, with exhibits explaining why Neolithic people chose this area to settle. To find the center, turn east off R512 at Reardons Pub in Holycross, take the first left afterward, and follow Lough Gur Road. The lake itself is a great place to explore and have a picnic.