The largest group of these sits on Inishowen and along the shores of Lough Swilly. Grianán of Aileach crowns Greenan Mountain, mostly an 1870s reconstruction over ground used for more than 4,000 years, with 360 degrees of view across Loughs Foyle and Swilly. Burt is the parish below it, holding the ruins of Burt Castle and Liam McCormick’s 1960s church of St Aengus. Further along the Swilly shore at Fahan, St Mura’s graveyard keeps a 7th-century cross-slab carrying the only known Greek inscription in early-Christian Ireland.
Two military sites face the same water. Fort Dunree stands on a promontory with its guns still in their emplacements, the last British post handed back to Ireland in 1938 and now a museum with signposted cliff walks and a café. Ned’s Point, a Napoleonic battery of 1812-13, can only be seen from outside, and the shoreline walk to it works best at low tide.
The south of the county has its own cluster. Donegal Town holds the fragment of Donegal Abbey by the mouth of the Eske and the Four Masters obelisk on the pedestrianised Diamond, both in the same small centre, with the Cistercian ruins at Assaroe further south near Ballyshannon. Letterkenny keeps Conwal Parish Church and St Eunan’s Cathedral at the top of the same street. Glebe House at Churchill and Lifford’s 1746 courthouse both need the car, and Glebe’s interior is tour-only and seasonal.
Mostly an 1870s rebuild, but the hilltop beneath is over 4,000 years old and the view runs 360 degrees across three counties.
The hillside under the ring-fort, where the ruins of Burt Castle and Liam McCormick's much-admired 1960s St Aengus's church stand within sight of each other.
Standing opposite St Eunan's since the 17th century, two hundred years before the cathedral, with a cast-iron roof and Jane Austen's niece in the graveyard.
27 of 27 shown — tap a pin for the place.
Greenan Mountain, donegal
Much of this hilltop ringfort is an 1870s reconstruction, but the site beneath is over 4,000 years old and the views are the real draw: 360 degrees over Loughs Foyle and Swilly, three counties, and the hills of Antrim beyond. Free and open in daylight hours; bring a windproof layer and expect no facilities.
Ballyshannon, donegal
Assaroe Falls was one of the Erne's great salmon leaps until the river was dammed for a hydro station around 1950, drowning it under a reservoir. What remains is still worth an hour, the roofless 12th-century Cistercian abbey, the restored Water Wheels mill with its café, and Catsby Cave, where Mass was said in secret under the Penal Laws.
Buncrana, donegal
The Grianán of Aileach is a restored dry-stone ring-fort on the hill above Burt, with a view over Lough Foyle, Lough Swilly and five counties. Below it stand the ruins of Burt Castle and Liam McCormick's much-admired 1960s church, St Aengus's.
Letterkenny, donegal
Conwal Parish Church has stood opposite St Eunan's Cathedral at the top of Letterkenny's Church Street since the 17th century, two centuries before the cathedral it now faces. Inside is an early-19th-century cast-iron roof; outside, the graveyard holds a niece of Jane Austen and the town's founder. It's an active church, so the interior is often locked outside services.
Doagh Island, donegal
The thatched cottages at Doagh Famine Village were lived in until the 1980s, and the family that grew up in them still guides the tours. It's an idiosyncratic, personal open-air museum on Inishowen – part Famine history, part eviction scene, part Irish wake, part haunted house – rebuilt after a fire in 2025.
Donegal Abbey, donegal
A fire reached the gunpowder stored in Donegal Abbey in September 1601, and the blast killed hundreds and ended the priory as a working monastery. Thirty years later four Franciscans compiled the Annals of the Four Masters here, a chronicle of Irish history that survives when the buildings largely didn't. What's left is a fragment by the mouth of the River Eske.
Inishowen Peninsula, donegal
Remarkably, a single stone slab bears the only known Greek inscription in early-Christian Ireland. St Mura’s monastic graveyard, with its 7th-century cross-slab and later medieval ruins, watches over Lisfannon Beach and the busy Lough Swilly marina.
Buncrana, donegal
Fort Dunree stands on a rocky promontory above Lough Swilly on the Inishowen Peninsula, its guns still in their emplacements. It was the last British military post handed back to Ireland, in 1938, and today holds a military museum, signposted cliff walks and a café with the lough laid out below.
The Diamond, donegal
At the centre of Donegal Town's pedestrianised Diamond stands a roughly 6-metre sandstone obelisk to the four scholars who, between 1630 and 1636, compiled the Annals of the Four Masters – the year-by-year record of Irish history down to 1616. Unveiled in 1938, its four faces carry Celtic interlacing and the compilers' names.
Churchill, donegal
The portraitist Derek Hill bought this 1828 rectory above Lough Gartan in the 1950s and filled it with more than 300 works by Picasso, Kokoschka, Yeats and others, hung as if he still lived there. He gave the house, its contents and 20 acres of garden to the state in 1981. Gardens are free and open daily; the house is tour-only and seasonal.
Kilmacrennan, donegal
Kilmacrennan was the inauguration place of the O’Donnell kings of Tyrconnell: the church rite at the abbey, the secular one out on Doon Rock beside Doon Well. The abbey ruins and 1916 garden are free and roadside, and the Lurgyvale thatched cottage nearby runs as a museum and tea rooms. Letterkenny is ten minutes away.
Inishowen Peninsula, donegal
Lenan Head Fort is the best-preserved of the seven forts built to guard Lough Swilly, kept intact not by care but by neglect - stripped of its guns in the 1950s and left standing ever since. You get three concrete gun emplacements on the cliff edge, underground magazines, caponiers and a deep defensive ditch, all fully exposed to the Atlantic. It is a derelict site with real hazards, so come in daylight and sturdy boots.
Letterkenny, donegal
Letterkenny is Donegal's largest town, strung along one long main street above the River Swilly. The Victorian cathedral of St Eunan and St Columba is the landmark, the free county museum sits in the old 1845 workhouse, and the Saturday market draws the crowds. Most people use it as a base for Glenveagh and the beaches rather than a destination in itself.
Lifford, donegal
Lifford is the county town of Donegal and seat of the county council, sitting where the Finn meets the Mourne on the border with Strabane. Its standout is the 1746 Old Courthouse, now a gaol-tour museum with a free heritage collection, paired with the cross-border Lifford Slí walk.
Malin More, donegal
Six portal tombs stand in a line across two fields above Malin Bay, one of the largest concentrations of megalithic tombs in Ireland. The chambers face different directions, hinting at deliberate alignment, and the westernmost is a double-capstoned dolmen you can walk right up to. It's unmarked working farmland, so it stays quiet.
Inishowen Peninsula, donegal
Mamore Gap climbs the Urris Hills at close to a 30% gradient, the high point of the Inishowen 100 loop. At the top sit St Eigne's holy well and a pilgrimage that still draws barefoot walkers, while the best view opens just as you start the descent toward Urris.
Ned’s Point, donegal
Ned’s Point Fort is a Napoleonic battery built in 1812–13 to block a French run at Lough Swilly, later re-armed with 6-inch guns and disarmed by 1907. You can’t go inside, but the exterior and the shoreline walk from O’Doherty’s Keep are free and open all year. Time it for low tide and a dry day.
Raphoe, donegal
The Bronze Age Beltany stone circle stands on a hilltop 2 km outside Raphoe – 64 stones in a 45-metre ring, best caught at sunset. In the town itself the Diamond market square is framed by two St Eunan's cathedrals, a Georgian school and the burnt-out shell of the bishop's castle.
Letterkenny, donegal
Letterkenny is called the Cathedral Town for one reason – St Eunan’s 73 m spire, visible on every approach. Inside, white Mountcharles sandstone carried up bucket-by-bucket gives way to a marble pulpit, Italian rib-vaulting and ten Harry Clarke windows high in the nave.
Tory Island, donegal
Donegal, donegal
Letterkenny, donegal
Milford, donegal
Rawros, donegal
Fahan, donegal
Glencolmcille, donegal
Arranmore Island, donegal
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