Tradition holds St Colmcille was born at Gartan in Co Donegal. The exact location of the saints birthplace is open to discussion. One tradition says the saint was born on a stone called the Leac na Cumha in the townland of Lacknacoo.
Leac na Cumha or the Stone of Sorrow is stone set into a large oval-shaped mound with a U-shaped setting of stones that opens to the north.
Leac na Cumha in Lacknacoo
The Leac na Cumha is located along th south-eastern edge of the mound. It is a flat slab of stone and its surface is covered in prehistoric rock art. The art consists of cup-marks c. 0.1m in diameter.
Leac na Cumha is covered in rock art
It is here on this stone that the saint is said to have been born. The site was marked on the 1st ed. (1836) OS 6-inch map as St Colmcille’s stones. Close to the mound is an enormous stone cross erected by Cornelia Adair in 1911.
Stone cross at Leac na Cumha in Lacknacoo
In the nineteenth century
it became commonplace for emigrants to spend their last night here on the Leac na Cumhadh – the Stone of Sorrows. As Colmcille had decided to exile himself to Scotland, they thought that sleeping here – where he was born – would make their sadness easier to bear (http://www.colmcille.org/gartan)
A short distance away are the ruins of an early medieval ecclesiastical site at Churchtown – Ráth Cnó . Tradition holds this was the place where St Colmcille’s family lived. It was said his family gave this land to the church so that a monastic settlement could be built here. The site over looks Lough Akibbon and Lough Gartan.
The site is still used as a turas by pilgrims who walk barefoot between the five marked stations. Believers follow the turas between Colmcille’s feast day on 9th June and the end of the turas season on 15th August, performing a series of prayers and actions at each stop (http://www.colmcille.org/gartan/3-03).
The most prominent features on the site is a small church marked as St Colmcille’s chapel on the 1st ed (1836) OS 6-inch map.
Medieval church at Gartan
According to the Donegal Archaeological Inventory this is probably the chapel described in 1622 as being in repair and having a thatched roof.
To the north of the church is a graveyard, at the centre of which are the foundations of a building said to be a monastic building.
Possible foundations of a monastic building
Two stone crosses also survive at the site and are part of the pilgrim stations.
Below the site is a holy well dedicated to the saint.
St Colmcille’s holy well at Gartan
Both of these sites are part of the Slí Cholmcille and directions can be found on this website.
Useful Links
Pilgrimage In Medieval Ireland 
First cupmarked stone I have come across to be described as a birthplace. But why not!
Reblogged this on Historical Tours Ireland.