The lighthouse you can look at but not land on
Rotten Island sits about 500 metres off the mouth of Killybegs Harbour, and there is no ferry to it. The tower has run automatically since 1959 and the rock is uninhabited, so this is a lighthouse you photograph from the mainland rather than one you climb. The clearest sightlines are from the Killybegs waterfront and from Carntullagh Head. To get close to the white granite tower you need a seasonal boat trip out of the harbour, roughly May to October and somewhere between €10 and €30 a head depending on the operator.
It still earns its keep. Run by the Commissioners of Irish Lights, the light marks the safe passage from St John’s Point past the rocks to the anchorage inside County Donegal’s busiest fishing port.
The name
The island’s Irish name is An tOileán Bréan, the formal station name Teach Solais An tOileán Bréan. Local lore ties it to Naomh Rotain, or Saint Rotain, a hermit said to have lived out on the rock; early English records simply anglicised the sound to ‘Rotten’, and that is the version that stuck.
Building it cost three lives
A light here was first proposed in April 1832. Mr Drury, the Inspecting Commander of the Coastguard, wanted it on Drumanoo Point; George Halpin, the Ballast Board’s inspector, argued for Rotten Island and won. The Board approved the scheme in November 1833, with statutory sanction from Trinity House soon after.
Halpin designed the tower and the keeper’s dwellings, and the Board’s own workmen built the tapering granite tower under his eye at a cost of around £8,700 (some records put it closer to £8,850). It was not built cheaply in any sense. On 15 September 1836, three of those workmen drowned when their boat capsized returning from the rock. The light was first shown on 1 September 1838, before the station was fully finished.
The station kept pace with the technology afterwards: it was automated on 7 January 1959, and on 1 February 1963 electricity was carried across the channel on an overhead cable, replacing the old paraffin burner. The tower and its buildings are on the Buildings of Ireland record as a protected structure.
Seeing it, and the specs
You cannot go inside, but there are decent ways to take it in:
- Headlands – Carntullagh Head and the Killybegs waterfront give clean sightlines. Photographers favour dawn or dusk, when the white tower stands out against the dark granite shore.
- Boat trips – seasonal cruises from Killybegs Harbour pass close to the island for views of the lantern, the metal walkway and the rubble-stone boundary wall.
- Wildlife – the isolation makes the rock a resting point for gulls and razorbills, and seals often haul out on the surrounding rocks.
For the technically minded:
| Feature | Detail |
|---|---|
| Tower height | 14 metres |
| Light height (MHWS) | 20 metres |
| Character | Fl WR 4s (white and red sectors, flashing every four seconds) |
| Range | White 15 nautical miles / Red 11 nautical miles |
Practical information
- Access – the island is uninhabited and the lighthouse operational. No footpaths, no regular ferry; all viewing is from the mainland or a licensed boat.
- Parking – free parking near Killybegs harbour and in the town, though spaces fill fast in peak summer, so come early. There is also limited roadside parking out towards Bruckless.
- Getting there – Bus Éireann and Local Link services connect Donegal Town and Letterkenny with Killybegs, a short walk from the quayside where the boat operators board.
- Boat tours – generally May to October, weather permitting. Operators vary, so check the harbour-side desks for departures.
- Safety – the water here is exposed to Atlantic swell and strong tides. Take the skipper’s advice and check the marine forecast before heading out.
Nearby
- St John’s Point Lighthouse – on the far side of the harbour mouth, the smaller beacon that completes the pair guiding boats into Killybegs.
- Killybegs Maritime & Heritage Centre – in the town, covering the fishing industry and the Donegal hand-knotted carpet trade.
- Slieve League – a short drive west, sea cliffs among the highest in Europe. (Ireland’s Majestic Cliffs)
- Arranmore Island – a ferry north to Donegal’s largest offshore island, with its own historic lighthouse and coastal trails. (Arranmore)
Pick a calm, clear day and, if you can, a boat: from the waterfront the tower is a distant white mark, but from the channel you get the lantern and the walkway close up. Check the tide tables if you want the rock at low water.