Knocknarea, Limestone mountain summit in County Sligo, Ireland

Knocknarea is a 327-metre limestone hill on the Coolera Peninsula west of Sligo town, its broad, rounded summit topped by a flat-topped cairn about 55 metres wide and 10 metres high. The upper slopes show grey rock through green vegetation, and the hill drops to fields and scattered buildings in the valley below.

Maeve's Cairn on the summit is about 55 m wide and 10 m high, the largest cairn in Ireland outside Brú na Bóinne, and is believed to date to around 3000 BCE; it has not been excavated. About 50 m north lies a partly ruined cruciform passage grave, and other small tombs line up north–south, possibly facing the Carrowmore tombs below. A 1 km embankment rings the eastern hilltop, where hut sites and stone-tool debris were found.

The cairn is called Miosgán Meadhbha in Irish, after Medb, a queen of Connacht in Irish mythology who was likely originally a goddess. Legend says she is buried upright in full armour, facing north toward her enemies in Ulster. The Neolithic tomb predates her by millennia, and folklore warns that damaging such tombs brings bad luck.

The walk to the top takes roughly 45 minutes and follows a clear path starting from a car park at the base. The terrain is open and the route offers good views when the weather cooperates.

In 2014 an archaeologist found 13 small bones and fragments of a Neolithic adult and a child in a hard-to-reach cave on Knocknarea. Radiocarbon dating put the adult at about 5,500 years and the child at about 5,200 years, the oldest human bones in County Sligo. They are evidence of excarnation, the practice of laying out the dead in a cave before depositing the bones elsewhere. The limestone hill has 14 caves on its north side.