The 10th-century ruins of Colmcille's abbey lie on a hillside to the north of Lough Gartan, beside a 16th-century chapel and an O'Donnell clan burial ground. It's a sign-posted 1km north of Glebe House along a country road.
One kilometre south of the ruins, near the southeastern (hikers and cyclists only) entrance to Glenveagh National Park, is the saint's birthplace , marked by a hefty Celtic cross erected in 1911. Beside it is an intriguing prehistoric cup-marked slab strewn with greening copper coins. It's popularly known as the Flagstone of Loneliness on which Colmcille supposedly slept.
