Near Mullingar lies the legendary Hill of Uisneach. In ancient Ireland, it was considered by druids to be the geographical and spiritual centre of the Emerald Isle. A rock known as Cat Stone, the Irish name “Ail na Mireann” means “stone of division”, marks the point where all five Irish provinces met. Éiru, in modern Irish Éire, is said to be buried under this rock. She is Ireland’s patron goddess.

The Hill of Uisneach or Ushnagh (Irish: Uisneach or Cnoc Uisnigh) is a hill and ancient ceremonial site in the barony of Rathconrath in Co Westmeath. It is a protected national monument. It consists of numerous monuments and earthworks—prehistoric and medieval—including a probable megalithic tomb, burial mounds, enclosures, standing stones, holy wells and a medieval road. Uisneach is near the geographical centre of Ireland, and in Irish mythology it is deemed to be the symbolic and sacred centre of the island. It was said to be the burial place of the mythical Tuatha Dé Danann, and a place of assembly associated with the druids and the festival of Bealtaine.

The site consists of a set of monuments and earthworks spread over two square kilometres. About twenty are visible, and the remains of at least twenty others have been identified under the ground. They include a probable megalithic tomb, burial mounds, enclosures, standing stones, holy wells and a medieval road. They date from the Neolithic to the early Middle Ages, showing that the site has been the focus of human activity for about 5,000 years. Several sites were excavated in the 1920s by R.A.S. Macalister and R. Praeger.

The summit is 182 metres (597 ft) above sea level and lies north of the R390 road, 8 km east of the village of Ballymore and beside the village of Loughanavally. The hill occupies parts of four adjacent townlands: Ushnagh Hill, Mweelra, Rathnew, and Kellybrook.