The vanished falls
The waterfall that Assaroe is named for no longer exists. Eas Aoidh Ruadh, the falls of Aodh Ruadh, was one of the great salmon leaps on the River Erne until, around 1950, the state diverted the river to feed the Cathaleen’s Fall hydro station and penned it behind a dam. The reservoir that formed is Assaroe Lake; the leap itself is now a concrete spillway. Local anglers have long campaigned to send a seasonal flow back over it during the salmon runs, but for now the roar that Ballyshannon grew up beside is gone.
Aodh Ruadh, in the older story, was a legendary High King who slipped and drowned in the falls; his daughter Macha is said to have succeeded him. The place has been fought over for a very long time. The Annals of the Four Masters record a slaughter here at Eas Ruaidh as far back as AD 836.
The abbey
Above the vanished falls stands what people really come for: the broken shell of Assaroe Abbey. Cistercian monks from Boyle Abbey founded it in 1178 and finished it in 1184, on land granted by Flaherty O’Muldory, lord of Tír Chonaill, who dedicated it to God and St Bernard. It survived a fire in 1377 and a raid in 1398, and declined after the Reformation, with the worst damage coming in the Cromwellian years. What is left is fragmentary: the west end of the church, part of the west gable, a stretch of the south wall. Look along the boundary walls and among the loose stones for the carved fragments salvaged from the church.
The poet William Allingham, born down the road in Ballyshannon, caught the ruin better than any guidebook:
Gray, gray is Abbey Assaroe, by Belashanny town, It has neither door nor window, the walls are broken down.
Ballyshannon Regeneration Group secured conservation funding for the ruins in 2026, so some of those broken walls may yet be steadied. Near them is the Abbey Well, Tobar na Bachaille, a holy well tied to the site’s early Christian tradition.
The Water Wheels and Catsby Cave
Across the old mill bridge downstream, the Cistercians’ water power has been put back to work. The restored twelfth-century mill, now called the Water Wheels, turns two rebuilt waterwheels and houses a coffee shop, restaurant, craft shop and a small museum on the medieval Cistercians in Ireland. The Abbey Mill Restoration Trust took on the mills and the ground around them in 1989. Opening is seasonal and not always predictable, so ring ahead (+353 71 985 1580) if the café is the reason you are going.
Follow the wooded riverbank north and you reach Catsby Cave, a grotto hidden behind sheer rock. Under the Penal Laws, local families used it to hear Mass in secret; a rough stone altar is still there, along with an old mill wheel thought to date from Cromwellian times.
What to see and do
- Walk the abbey grounds and graveyard – uneven, grassy and quiet, and good for photography.
- The Water Wheels – catch the waterwheels turning, browse the craft shop, and pause in the café and museum; hours are seasonal, so phone first.
- Catsby Cave – the Penal-era Mass shelter, a short walk up the riverbank.
- Fish the lake – Assaroe Lake holds brown trout, pike and coarse fish; bank fishing is allowed on designated north-shore stretches with an Inland Fisheries Ireland permit.
- Combine with the coast – Rossnowlagh and Bundoran beaches are both a short drive.
Practical information
- Location and access: about 1 km north of Ballyshannon off the N15, signed; free to enter and open dawn to dusk.
- Parking: a small car park by the abbey cemetery, with more near the mill; both fill fast on summer weekends.
- Footwear: the ground is uneven and slick after rain, so bring proper shoes and a waterproof.
- Getting there: Bus Éireann routes 64/65 stop in Ballyshannon; the abbey and mill are about a 15-minute walk north along the river. There are no ticket desks or tours; the whole place is self-guided.
If you only have an hour, give it to the abbey and Catsby Cave. The lake is pleasant, but you can find its like all over Donegal; the drowned salmon leap and the Mass cave you cannot.