Just over 2 kilometers to the south of Sligo and an easy walk from the center of town, Cairns Hill is an mysterious and little-known neolithic landscape, despite the urban sprawl that has crept up around it. Carns Hill is a double hill, with the higher west cairn 123 meters, and the slightly lower east cairn at 112 meters above sea level. As the name suggests, the summits are capped by cairns, two huge unopened and undisturbed examples of Irish neolithic passage graves. The two monuments are known as the east cairn and the west cairn, and both are sited on the highest parts of the flat summits.
The west cairn has an open view of the horizon and looks to Sliabh Dá Eán just south, Knocknashee, Doomore and Croghaun to the south west, Knocknarea to the west and Benbulben to the north. The east cairn is shrouded in a thick growth of trees, which make the walk to the site quite pleasant, but obscures all views views to the horizon. Lough Gill, the Lake of Brightness lies just to the east of Carns Hill, and the river Garavogue flows around the east side of the hill and then flows into Sligo Bay. Both cairns are a short walk from the modern waterworks between the two sites.
The East cairn
Parking by the waterworks, take the forest walk path running east; after a few minutes you can take the first trail to the right to climb to the cairn, or continue through the forest to visit the cave. All the major megalithic sites in County Sligo have associated caves, and there are two in Cairns Hill, one close to each of the cairns.
The cave is well worth visiting, if only because it is the easiest cave in County Sligo to visit. Follow the forest trail for 10 minutes and the cave will appear on the right. The cave is shallow, some 5 meters deep, and big enough to stand upright in the opening. It is located in a cliff overlooking the river Garavogue below. A seam of chert runs through the roof of the cave.
To visit the cairn, turn back the way you came, and after a few minutes take a left path and follow to the highest point. The cairn is covered with young trees and scrub - ash, sycamore and hazel, so that you might easily miss it and walk by: it is not that well known, even in Sligo town less than a mile away. The cairn is quite massive, being about 45 meters in diameter and some 10 meters high. It is composed of chunks of quarried limestone, and is most likely kerbed and strewn with quartz. The site was cleared and surveyed by archaeology students at NUI Galway in 2004, but rapidly became overgrown again. As the cairn is shrouded in forestry, there is no view to the horizon or Knocknarea just 8 km to the west, but using maps and Google Earth we can get some idea of the alignments.