McDermott’s Castle In Roscommon: A Place Like Something From Another World

A grand aul hidden gem

mcdermott's castle in roscommon
Photos by ianmitchinson (shutterstock)

There are few castles in Ireland as unique as the mighty McDermott’s Castle.

As you can see from the photo above, it’s quite literally plonked on a little green island smack bang in the middle of a lake.

Although McDermott’s Castle gets far less attention than the likes of the most haunted castle in Ireland and Blarney Castle, it’s still well worth a visit.

In the guide below, you’ll find out everything that you need to know about this incredible fairytale-like castle.

Welcome to McDermott’s Castle

McDermott's Castle roscommon
Photo by 4H4 Photography (Shutterstock)

You’ll find McDermott’s Castle in County Roscommon on Lough Key, 3km northeast of the town of Boyle.

Stretching around 10km across and forming a rough circular shape, Lough Key contains over 30 islands scattered throughout its chilly waters.

One of these islands is aptly named ‘Castle Island’ and it’s here that you’ll find the ruins of McDermott’s Castle.

A tale of tragedy 

mcdermott's castle in roscommon
Photos by ianmitchinson (shutterstock)

Local legend tells the story of a girl called Una, the daughter of the McDermott chief, who fell in love with a boy from a lower class.

Una’s father refused to let her leave the island, in the hopes that this would deter the budding relationship.

Unbeknownst to her father, Una’s boyfriend began swimming across Lough Key to reach the castle. It was during one of these crossings that tragedy struck, and the boy drowned.

It’s said that Una died from grief and that both she and her partner have remained buried beneath two intertwined trees on the island ever since.

Getting to McDermott’s Castle

If you fancy seeing more of Castle Island and McDermott’s Castle, there are several tour providers that offer trips to and around the island.

If you’re visiting the area, make sure to spend some time in Lough Key Forest Park. It’s home to around 800 hectares of gorgeous, picturesque wood and parkland with a lake and several wooded islands.

For those exploring the park, take some time to ;

  • Check out the observation tower
  • Have a gander at the wishing chair
  • Stroll through the underground tunnels.
  • Ramble along the Trinity Bridge
  • Have a snoop around the Bog Garden
  • Soak up some of the history of the area in the visitor centre and soak up some of the areas rich history

Have you visited McDermott’s Castle? Did you hop on one of the boat tours? Let me know in the comment section below!

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  1. Beautiful spot! We live in the US, but I have visited there and some other lovely places in Roscommon with my family. Before it was McDermott’s it was known as McGreevy castle. The McGreevy clan was active in the area, and also donated the land for Boyle Abbey to be built. The folks who are the guides at Lough Key still have a McGreevy involved in their venture. A long time ago, the McDermotts defeated the McGreevys and took over the castle. The whole place is magical and well worth a visit.

  2. I would very much like to learn more as my ancestors are from there .I am a McDermott and would very much appreciate any information you could give me on them.

    • We are related to Andrew McDermott born (1849-1853) in Boyle.
      Parents may have been Matthew McDermott and Mary Mulligan but cannot verify.
      Andrew moved to America at age 20 and had 8 children.
      he may have served in the British (Army or Navey) and may have deserted in 1873 not proven.
      Ed McDermott

  3. The lad Una Mc Dermott was in love with was Thomas Og Costello from the wealthy Norman Irish Clan they had 3 Castles and nine Manor houses and over 30 thousand acres before losing most of it to Vicount Dillon’s family during Cromwells time . They had been in battle with the McDermotts over land for years that’s why the families didn’t aprove of the relationship Patrick de Nangle Costello Lord of Glashnacree in the kingdom of Kerry

  4. Greetings from a McDermott in paradise: Costa Rica! Me an my son are planning to visit the castle as soon as the pandemic is over. Many thanks for the video and the history. Looking foward to the visit…BettyAnn McDermott.

  5. Wow, thought I knew everything about my ancestors and just stumbled on this hidddn gem , cant wait to go and explore as soon as normality returns

  6. My 4 times Great Grandmother is Mariam (Mary) Mc Dermott Christening Mar 2 1839
    Tibohine, Roscommon, Ireland.
    Shaun, Betty Ann,Rodney are we related??


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