Bay Lough sits in the Knockmealdown Mountains on the Tipperary-Waterford border, and it is not a lake that leaves you indifferent. The water is dark. The hills close in on three sides. On a grey morning, with mist sitting on the surface, it feels older than the mountains around it. Come here for the walk. Come here for the views from the Vee Gap. But if you know the story of Petticoat Loose, you’ll find yourself glancing over your shoulder on the way back down.
The legend of Petticoat Loose is one of the oldest and most persistent in Munster. It has been told and retold for at least two centuries, and it is still told today. That kind of staying power means something.
Who Was Petticoat Loose?
The woman at the centre of the legend was called Mary Hannigan. The name Petticoat Loose was a nickname — and in the rural Ireland of the 19th century, it was not a compliment. A woman described as “loose” was one who lived outside the accepted rules. She was ungovernable. She refused to be what she was supposed to be.
Mary Hannigan, by all accounts in the tradition, was exactly that. She worked in a pub or inn, which was already unusual for a woman of the time. She was known for her dancing, her sharp tongue, and her willingness to outdrink anyone who challenged her. Some versions of the story describe her as a healer or a cunning woman — someone with knowledge that made her neighbours uneasy. Others say she was simply a woman who refused to be controlled, and that was enough to make her a figure of fear.
Whether Mary Hannigan was genuinely wicked or simply inconvenient to the social order depends on who tells the story. What all versions agree on is this: after her death, she was not allowed to rest.
The Curse and the Condemnation
The punishment handed down to Petticoat Loose was a task — and a deliberately impossible one. She was condemned to empty Bay Lough using only her sewing thimble.
Bay Lough is believed, in local tradition, to be bottomless. Whether that is geologically accurate is a separate question — it is a glacial corrie lake carved by Ice Age movement, and corrie lakes can be surprisingly deep — but the point of the legend is clear. She was given the smallest vessel imaginable and set to work on an infinite task. It is the Irish equivalent of Sisyphus and his boulder. The punishment was not just hard. It was designed to last for ever.
Some tellings of the story say that Petticoat Loose can be encountered near the lake at night. Travellers crossing the Knockmealdowns after dark — particularly those who had been drinking — claimed to have seen or heard her. She would give chase, her petticoat flapping in the wind, driving the traveller forward in terror. The only safety was a bridge or a stream. Running water, in Irish folklore, is a barrier that spirits cannot cross. Reach the water, and you were safe. Don’t reach it, and you weren’t.
The geography of the Knockmealdowns — mountain passes, dark roads, few crossings — made the legend especially effective as a night-time warning. Whether the warning was about the supernatural or about the dangers of the mountain itself probably mattered less than the result: people moved quickly through these hills after sunset.
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Bay Lough: The Place Behind the Legend
Bay Lough sits at around 260 metres above sea level in the Knockmealdown Mountains. It is a glacial corrie lake — formed when a glacier carved a hollow into the hillside during the last Ice Age, and the hollow filled with water when the glacier retreated. The result is a dark, oval lake enclosed on three sides by steep ground, with a natural drama to it that has nothing to do with Mary Hannigan.
The lake is surrounded by rhododendron bushes. From late May through June, these bloom a vivid purple that contrasts sharply with the dark water and the green of the surrounding slopes. It is one of the better visual spectacles in Munster, and it is almost entirely unknown outside the region.
The Knockmealdown Mountains themselves reach a high point of 792 metres at Knockmealdown peak. The range runs roughly east to west, separating County Tipperary to the north from County Waterford to the south. From the ridge on a clear day, you can see across four counties. The walking is varied — valley paths, exposed ridgelines, and everything in between.
Getting to Bay Lough
The most practical starting point is the Vee Gap, one of the most dramatic mountain passes in Munster. The Vee is on the R668 road between Clogheen in County Tipperary and Lismore in County Waterford. The road winds up through the mountains with views across the Suir Valley and the Tipperary plain stretching away to the north. Even if you don’t plan to walk, the drive through the Vee is worth doing.
From the car park at the Vee, the walk to Bay Lough takes around 20 to 30 minutes each way. The path is reasonable underfoot but can be muddy after rain. Proper walking boots are worth wearing — trainers will do the job on a dry day, but the Knockmealdowns are wet mountains and conditions can change.
There are no facilities at the lake. The nearest services are in Clogheen, a small village to the north with a pub and a petrol station. Lismore, to the south, is larger and has more options — including Lismore Castle, which is one of the most striking buildings in County Waterford and well worth a stop.
Samuel Grubb and the Vee
Petticoat Loose is not the only story attached to this part of the mountains. The Vee Gap has its own curiosity: the grave of Samuel Grubb, a Quaker landowner who, according to local tradition, asked to be buried upright on the ridge so that he could look out for ever over his land in Tipperary. Whether the request was granted in exactly those terms is debated, but his memorial is visible from the road, and it adds another layer to a landscape already well stocked with stories.
The broader Knockmealdown area sits within reach of several significant historical sites. The Rock of Cashel is around 30 kilometres to the north — one of the most important early Christian sites in Ireland. Ormond Castle in Carrick-on-Suir, a 16th-century manor house built for the Butler family, is within easy reach to the east. The mountains themselves served as refuge and contested territory across various periods of Irish history, and that past sits quietly in the landscape.
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Walking Events in the Knockmealdowns
If you want to explore the Knockmealdowns properly and with local guidance, the Rhododendron Walking Festival is the main annual event for the area. It takes place on the June Bank Holiday weekend and offers a programme of guided walks across the range at various difficulty levels. Bay Lough and the Vee Gap are regular inclusions in the programme.
The festival draws walkers from across Ireland and from further afield. It’s a well-organised event that gives you access to routes and local knowledge that would take considerably longer to find on your own. Knockmealdown Active also organises walks and events throughout the year — check their website for current dates and booking details.
What the Legend Really Tells Us
Stories like the legend of Petticoat Loose do not survive for two centuries by accident. They carry something that people have found worth passing on.
One reading is straightforward: it is a ghost story designed to make mountain crossings after dark feel more dangerous than they already were. That was useful in a time when the Knockmealdowns were a genuine barrier between communities, when the road through the Vee was rough and poorly lit and accidents happened.
Another reading is more uncomfortable. Mary Hannigan was a woman who refused to conform. She drank. She danced. She worked in a pub. She had knowledge or skills that made her neighbours uneasy. The legend turned her into something to be feared and avoided — a supernatural threat that lurked in the darkness. In that reading, the legend is a record of how rural Irish society dealt with women who stepped outside the lines.
Both readings can be true at the same time. The legend of Petticoat Loose is, by any measure, an effective piece of storytelling. The image of a woman crouching at the edge of a bottomless lake, century after century, thimble in hand, with the water never getting any lower — that is a powerful image. It lodges in the mind. It explains why people are still talking about Mary Hannigan in the shadow of the Knockmealdowns two hundred years after she allegedly lived.
Bay Lough is worth a visit for the walk alone. On a clear day in late spring, with the rhododendrons in bloom and the Suir Valley laid out below the Vee, it is as good as a mountain lake gets in this part of Ireland. The legend is a bonus — or a reason to keep moving before dark.
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Image credit: Love Ireland archive
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