Don O’Neill Island is located on the northeast coast of Ireland, within and off the western shore of Strangford Lough. It offers an anchorage close northwest to the larger of the two islands that offer gravel beach landings.

This is an exposed day anchorage that is good for a landing on the island in settled conditions. It would not be ideal for an overnight stay where it may become uncomfortable. The Lough's enclosed body of water provides sheltered sailing in all weather, all tides and ample marks to make daylight navigation straightforward.

Keyfacts for Don O’Neill Island

Position and approaches

Haven position

54° 24.650' N, 005° 37.130' W

Close northwest of the larger south-western Don O’Neill Island in approximately two and a half metres.

What is the initial fix?

Approximately 400 metres northeast of the smaller and more northeasterly Don O’Neill Island.

What are the key points of the approach?

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What's the story here?

The Don O’Neill Islands are located almost at the centre of Strangford Lough, about 1½ miles northwest of the Narrows and 1.2 miles northwest of Killyleagh. They consist of a larger and a smaller island linked by a causeway at low tide. The larger roughly D-shaped southern island, which is known as Dunnyneill Island, is formed from a small drumlin. It is approximately 100 metres long and rises to a height of approximately 13 metres above sea level and is currently covered by trees. The island has a steep eroding cliff facing towards the mouth of the Lough and a narrow detached gravel bar, barely visible at high tide, approximately 200 metres to the east.




The smaller island is located 100 metres to the northeast of the main island and is made up of sand and gravel topped by centuries of bird compost which supports the grass and fauna. It is roughly oval in shape, approximately 65 metres long and rises to a height of approximately 3.4 metres.

There are no defined landing places on the island although it is possible to land on Dunnyneill Island's northwestern-facing gravelly shore with relative ease.

How to get in?

Details of the approaches, tidal timings, the run up The Narrows and onward to Killyleagh, on the Lough's western shore, are covered in the Entering and exiting Strangford Lough route description. Having entered Strangford Lough it is safe to make a direct approach, to come north around the island from the centre of the Lough using the Don O’Neill Initial Fix.




This lies between the smaller northern Don O’Neill Island and the Limestone Pladdy. Racemark No. 5 normally lies in this area. It is approximately a distance of 1.8 miles on a bearing of 324° T from Ballyhenry Point.




There is deep water all around the island so it is also possible to cut between Long Rock and Don O’Neill Island's southwest side from the Lough's entrance. However, deeper draught vessels taking this pass should make note of Neil Reef, with 2.1 metres over it, which is close to this approach across the Lough.




When rounding the island from the south give it a wide berth as a narrow gravel bar, barely visible at high tide, lies approximately 200 metres to the east of the southern islands. Direction for Holm Bay may be used by vessels approaching from the Killyleagh and the Quoile River.




From the Initial Fix proceed westward through the gap until the larger island is immediately south and then turn to port to approach the anchorage.




The anchorage is ideally approached on a rising tide, and as it is somewhat exposed, so come in as shallow as possible to maximise the protection.

Land on the island's gravelly northwest-facing beach. At low tide, there is a boulder field on its closer approaches so take it steady with an outboard when coming in as it would be easy to strike a rock with the propellor.

Why visit here?

Don O’Neill Island, locally known as 'The Dunner Neil' or 'Dunny Neil', is believed to have acquired its name from the semi-mythical King Niall of 'Niall of the Nine Hostages'. The 'dun' element to the name, meaning 'fort', could have referred to a defensive enclosure on the main island and the 'O'Neill' referring to the prehistoric Irish king. Others believe the island's name is similarly derived but from the Gaelic 'Dun-na-n-giull', meaning 'the fort of the hostages'.




Niall is presumed to have been a real person, or at the very least semi-historical but most of the information about him that has come down to us is regarded as legendary. He is the ancestor of the 'Uí Néill' family that dominated Ireland from the 6th to the 10th century. Legend has it that in the late 5th century he was king of Ulster and he took hostages from nine kingdoms around the British Isles of which one was St Patrick. There is no direct evidence to indicate that this was the island where Niall confined his high-status hostages. No constructions or ruins relating to the conception of a fort or prison on the island have been uncovered from that period, but it would have been an ideal site for a Niall to have constructed one. Unique among all the islands of Strangford Lough, the Don O’Neill Islands are strategically located to command both the narrows at the Lough’s mouth and the entrance to the Quoile Estuary.




This strategic position would not be overlooked in later centuries as recent excavations have revealed the island hosted a trading emporium during the 6th and 7th centuries. Ulster, during this period, was a great maritime kingdom. It was here that the wealthy merchants of the high-status settlement sites in western Britain and Ireland sailed to in order buy and sell goods. Likewise, merchants from as far afield as modern-day Russia, Germany, Iceland and France came to this tiny little island to trade wine, pottery and other luxury products for furs, seal skin, slaves and famed Irish wolfhounds.




It is believed that the island would only have been occupied when seaborne merchants arrived. Members of the local 'Dál Fiatach' dynasty would have travelled to Don O’Neill Island with their retinue and provided hospitality for the merchants whilst trading was conducted. This encouraged the merchants to continue dealing with the local secular elite, rather than seek trading arrangements with rival neighbouring kingdoms. But the occupation would eventually be abandoned after it was slowly eclipsed by trading routes located in the North Sea zone. The brusque trade left behind fragments of its business such as glass an Anglo-Saxon claw beaker, nails, bone combs and animal bones.




The footprint of a long rectangular hut discovered on the island dates here from around 900 AD. This dates to the time of the Viking invasions when it would have made an ideal forward operating base for their activities. It is believed the occupation extended into John de Courcy’s Lordship of Ulster following his Anglo-Norman invasion of the kingdom of 'Dál Fiatach' in 1177. The island's strategic position and easily secured boundaries would have made it attractive during this period of political change and instability. In the 17th century, the island was, according to local tradition, used as a leper colony and was used for the burial of victims of the 1854 cholera outbreak.




Today the diminutive island, which should perhaps be referenced as islands as it comprises two separated by an inter-tidal peninsula, is a lovely place to come ashore and take it all in and have a picnic. Family boats will find it a great location to let the kids off to roam as the stones and shells they will find around the Island are remarkable. Please be conscious that the smaller Don O’Neill Island to the northeast is an important nesting site for Sandwich, Arctic and Common Terns that arrive from the edge of the Antarctic or Africa to nest in April-June. During this period there should be no landing on the smaller island. Likewise, on the larger island, one should not go above the high water mark to minimise any distress to birds during the nesting season.

What facilities are available?

None, this is a secluded island with no resources.

Any security concerns?

Never a problem known to have occurred at Don O’Neill Island.

With thanks to:

Brian Crawford, local Strangford Lough boatman of many decades. Photography with thanks to CSMA Club Photography. eOceanic would like to thank Quoile Yacht Club for hosting our survey boat during the survey of Strangford Lough.