Dublin's Islands

Dalkey Island & The Muglins

Dalkey Island (Deilginis – “thorny island”), with its prominent Martello Tower, marks the southern end of Dublin Bay. (Photo by ww2censor)

The 9-hectare / 22-acre treeless island is located less than 300m offshore, near the upmarket suburban village of Dalkey, 3 km / 2 mi south of Dún Laoghaire.

Nowadays unpopulated, Dalkey Island is believed to have had human inhabitants as early as the Mesolithic Era (Middle Stone Age); artefacts from the island, now housed in the National Museum in Dublin, re estimated to be almost 6000 years old. Settlers continued to use the site through the Iron Age and Early Christian period. A promontory fort was located at the northern end of the island, its presence still visible today in the form of a ditch.

According to folklore, Vikings used the island  in the C9th / C10th as a base for keeping and selling slaves captured in raids up and down the Irish coast and across the Irish Sea in Wales.

Mainlanders fleeing the Black Death took refuge on Dalkey Island in the C14th.

A custom started in the C18th of making an annual festive visit to crown the “King of Dalkey, Emperor of the Muglins, Elector of Lambay and of Ireland’s Eye, Defender of his own Faith and Respecter of all Others” was eventually suppressed by the Government, who (rightly) suspected that the United Irishmen were involved; revivals have been attempted sporadically.

Saint Begnet’s church was probably constructed in the late C9th on the site of an earlier wooden structure abandoned when the Vikings took over the island. It was most likely already in ruins when  builders used it as living quarters while installing the nearby Martello Tower and gun battery in 1804. The waters of Saint Begnet’s Holy Well are supposed to cure rheumatism. 

(The Saint herself is said to have been a C6th Irish virgin princess who became an Abbess in Northumbria; how she came to be Patron of Dalkey is a mystery.)

The Martello Tower, which gives Dalkey Island its distinctive silhouette, was one of eight erected along the Dun Laoghaire coastline as part of a necklace of defensive fortifications constructed around Ireland by the British Admiralty against the threat of French invasion during the Napoleonic era.  

There have been goats on the island since at least the early 1800s, but the current animals are not descended from the first herd, removed c. 1980.

The most common creatures on the island itself are rabbits, but the shoreline is a good place for birdwatching and is occasionally used by seals.

Dalkey Island is a favourite with kayakers, especially on the flooding tide, when it is easier to go around it in an anti-clockwise direction. There can be a substantial overfall at the southern end, which can be extremely challenging for the kayaker, especially in a southeast wind. 

Maiden / Carraig Rock, Clare Rock and Lamb Island, all to the northwest, form part of the same ridge as the Island; more of the reef is visible at low tide.

The Muglins are a separate chain of rocks  to the east of Dalkey Island.  At least thirteen ships are known to have come to grief on these rocks before 1879, when they were fitted with a distinctive beacon to warn shipping of their presence; this was replaced by a small (14m) lighthouse in 1979.

Some say that the Muglins were used for several centuries to chain prisoners convicted of piracy, left to drown at high tide as a warning to others. The cadavers of the notorious sailors who in 1765 murdered the Captain and passengers of the Earl of Sandwich in mid-Atlantic, put ashore near Hook Head and supposedly buried 250 bags of gold at Dollar Bay before being caught and hanged in St Stephen’s Green, were exhibited on the Muglins.

The waters around Dalkey Island are much used for sailing, angling and diving. The channel between the island and the mainland is very deep, and was once considered as a suitable location for an oil terminal. However, the district’s powerful residents arranged for the terminal to be taken elsewhere.

Dalkey Island & The Muglins can be reached by hired boat from Bulloch Harbour or Colliemore Harbour.