Atlantic Megalithic & Iron Age Monument Building

Deep-time settlement, megalithic and Bronze/Iron-Age ritual landscapes before recorded states.

1 chapter

400 - 1200

Celtic Christianity spread through this region via monastic foundations that became the nodes of a learned, artistic, and ritual network connecting remote Donegal coastlines to inland Cavan and Monaghan. St Columba (Colm Cille) gives his name to Gleann Cholm Cille, where the Turas pilgrimage—15 stations around standing stones and a holy well—Christianised a pre-existing sacred landscape. At Clones, St Tiernach founded a monastery whose round tower and high cross still mark the town centre; at Drumlane in Cavan, an Augustinian abbey and round tower became one of the first four National Monuments in Irish state care. Kilmore Cathedral in Cavan, founded in the 6th century by St Felim, preserves a Romanesque doorway moved from Trinity Island during the 17th century—a material trace of the monastic building tradition. These monastic sites did not just worship; they created the parish boundaries and feast-day calendar that still structure when communities gather. Pattern days at holy wells often fall on the feast days of the saints who founded these monasteries, tying the modern pilgrimage calendar directly back to this era.

1200 - 1607

Gaelic clan lordships—O'Donnell in Donegal, O'Reilly in Cavan, MacMahon in Monaghan—controlled this region from tower houses and crannog castles that still dot the landscape. Donegal Castle, built by the O'Donnell chieftains in the 15th century beside the River Eske, was the seat of Tír Conaill's rulers. Cloughoughter Castle, an O'Reilly stronghold on a crannog in Lough Oughter, withstood siege during the Confederate Wars. Doe Castle, built by the MacSweeneys in the 1420s on Sheephaven Bay, shows the Scottish tower-house influence that entered through Gaelic mercenary families. At Ballyshannon, the O'Donnells built a castle overlooking the River Erne crossing around 1423, controlling a strategic ford. This era ended catastrophically: on 4 September 1607, the Earls of Tyrone and Tyrconnell boarded a ship at Rathmullan on Lough Swilly and sailed into permanent exile—the Flight of the Earls that collapsed the Gaelic order and opened the way for the Plantation of Ulster. Rathmullan's Carmelite friary ruins and the pier where the earls departed still face each other across the water. The clan system left more than ruins: it shaped the parish boundaries, the patterns of landholding, and the inauguration sites that later became festival gathering points.

1609 - 1695

The Plantation of Ulster (from 1609) divided this region into confessional communities whose parallel ritual calendars still structure festival life today—but are rarely acknowledged in the same frame. Basil Brooke added a Jacobean wing to the O'Donnell keep at Donegal Castle, turning a Gaelic chieftain's seat into a Planter's residence—a physical metaphor for the layered, contested reality of the Plantation. At Raphoe, the Church of Ireland cathedral became the established church's seat, while Catholic worship was forced into hiding. At Kilmore in Cavan, the medieval cathedral passed to the Church of Ireland, and a Romanesque doorway was moved from Trinity Island to the new 17th-century building. Ballyshannon became a Plantation garrison town with a new castle and bawn. Donegal was 'planted but did not become part of Northern Ireland'—the Plantation's consequences played out differently here than in the six counties, producing a Protestant community that was indigenous to the border counties rather than an extension of the Northern state. The marching season, harvest thanksgiving, and bonfire traditions that Protestant communities maintain in Donegal, Cavan, and Monaghan date to this era of confessional division. The legacies of the Plantation are still contested: what one community calls settlement, another calls dispossession, and the same landscape holds both stories.

1695 - 1845

The Penal Laws era created a dual religious landscape that still marks this region: Protestant churches stood visible and established, while Catholic worship retreated to hidden Mass rocks and holy wells whose pattern days (Patrún) preserved pre-Christian seasonal rhythms under a Christian veneer. Mass rocks (Carraig an Aifrinn) like those at Carndonagh in Inishowen and Gubaveeny in Clontibret, Monaghan, were outdoor altars where priests celebrated secret liturgies—often repurposing older sacred sites on megalithic tombs or ring forts. Holy wells became the focal points of community ritual when church buildings were forbidden or inaccessible: St Davnet's Well at Tydavnet (pattern day June 13), St Tiernach's Well at Clones (April 4), and Tobar Cholm Cille in Gleann Cholm Cille all maintained pattern day observances that layered Christian saints' feast days onto older seasonal markers—St Brigid's Well at Lisdrumturk falls on 1 February (Imbolc), St John's Well on 23 June (midsummer). Crucially, these pattern days survived because of folk attachment, not institutional Catholic support—after the Synod of Thurles (1850/51), the hierarchy would actively try to suppress them as 'semi-pagan remnants'. The sean-nós song 'An raibh tú ag an gCarraig' ('Were you at the Rock?') may encode a coded invitation to a Mass rock gathering, preserving the era's clandestine ritual network in oral tradition.