Don O’Neill Island is located within Strangford Lough on the northeast coast of Ireland. It is an anchorage close north-west to the larger of the two islands that offer 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 enclosed stretch of water provides shelter sailing in all weather, all tides and has 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. A course of due west from here will take a vessel between the extended drying patch, that surrounds the northeasterly smaller Don O’Neill Island, and Limestone Pladdy to the north.

What are the key points of the approach?

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How to get in?

The Don O’Neill Islands are located in about the middle of Strangford Lough, about 1½ miles north-west of the Narrows. They consist of a larger and a smaller island linked by a causeway at low tide. The larger roughly D-shaped island, which is known as Dunnyneill Island, is formed from a small drumlin. It is approximately 100 metres long and rises to a height approximately 13 metres above sea level.

The southern side of the island is made up of sand and gravel topped by centuries of bird compost which supports the grass and fauna. It is defined by a steep eroding cliff which faces towards the mouth of the Lough. A narrow gravel bar, barely visible at high tide, lies approximately 200 metres to the east of the islands.


Details of the approaches, tidal timings and the run up the Narrows to about a ½ below Strangford are covered in the Entering and exiting the Strangford Narrows 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 lays up an easterly approach between Limestone Pladdy and the smaller Don O’Neill Island to come round to the anchorage. Proceed 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, come in as close as possible to maximise the protection. The island has no well-defined landing places although it is possible to land on the northern shore with relative ease.

Why visit here?

Don O’Neill Island is often locally known as ‘The Dunner Neil’ or ‘Dunny Neil’. The island's name is believed to have been derived from Niall of the Nine Hostages. Niall was a fifth-century king of Ulster who took hostages from nine kingdoms around the UK, one of whom was St. Patrick and was the ancestor of the Uí Néill family that dominated Ireland from the 6th to the 10th century.

The dun element to the name, meaning ‘fort’, would refer to an enclosure on the main island and the O’Neill would refer 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’ indicating that this was the island where Niall confined his high-status hostages. There are no constructions or ruins relating to the conception of a fort or prison on the island from that period, but it would have been an ideal site for a Niall to have constructed one.

Uniquely, of all the islands in Strangford Lough, the Dunnyneill Islands are strategically located so as to command both the narrows at the Lough’s mouth and the entrance to the Quoile Estuary. This strategic position was not overlooked in later centuries as recent excavations have revealed evidence of a seventh-century trading emporium being sited on the island and a long rectangular hut was here from around 900 AD, during the Viking invasions.

The seventh-century trading emporium is perhaps the most remarkable find. Ulster, during this period, was a great maritime kingdom and its wealthy merchants travelled the seas to 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. The island was to go on to become a leper colony according to local tradition and was used for the burial of victims of the 1854 cholera outbreak.

Today the diminutive island, that should perhaps be referenced as islands as it comprises two separated by an inter-tidal peninsula, is a lovely place to come ashore and let the kids off to roam.
The stones and the 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.