Sixteen entries, and they are not all castles in the same sense. Castle Ward on Strangford Lough is a National Trust country house with two faces, a prim Palladian front and a Georgian Gothic rear, the result of an 18th-century couple who could not agree; the estate runs to about 820 acres, 13 miles of trails, a working corn mill and the farmyard that played Winterfell. Hillsborough Castle, twenty minutes south of Belfast, is a working Georgian residence in 100 acres of gardens, with a guided State Rooms tour or a cheaper gardens-only ticket.
The medieval end of the list is smaller and mostly free. Dundrum’s round Norman keep sits on a rocky ridge with the Mournes filling the view south. Clough Castle is a motte-and-bailey with a ruined tower on top and a short steep climb to views over Lecale. Kilclief, near Strangford, is the earliest datable tower house in the county, built between 1413 and 1441, and Narrow Water is a 1560s tower and bawn guarding the mouth of the Newry River.
Check two things before you set out. Portaferry Castle is closed for structural repairs and will not open in 2026, so it is an exterior stop. Gilford and Ballyedmond are private estates rather than visitor attractions.
One house with two faces, Palladian at the front and Georgian Gothic at the back, on 820 National Trust acres with the Winterfell farmyard.
The monarch's official Northern Ireland residence twenty minutes from Belfast, with guided State Rooms and a cheaper gardens-only ticket for the 100 acres.
A round Norman keep on a rocky ridge with the Mournes filling the view south and a coastal path below it to the harbour.
A free Anglo-Norman motte topped by a ruined tower house, with a short steep climb to views across the Lecale countryside.
14 of 15 shown — tap a pin for the place.
Strangford, down
Castle Ward is one house with two faces – a prim Palladian front and a Georgian Gothic rear, the result of an 18th-century couple who could not agree. The National Trust estate on Strangford Lough runs to about 820 acres, with over 13 miles of trails, a working corn mill, and the farmyard that played Winterfell in *Game of Thrones*.
Royal Hillsborough, down
Hillsborough Castle is the official Northern Ireland residence of the British monarch and the home of the Secretary of State, a working Georgian house set in 100 acres of gardens 20 minutes south of Belfast. You can tour the State Rooms with a guide or buy a cheaper gardens-only ticket and spend the day among walled gardens, a lake and a rose garden. Managed by Historic Royal Palaces since 2014.
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Dundrum Castle's round keep sits on a rocky ridge with the Mournes filling the view south. Below it, a coastal path follows a disused railway through salt marsh to the harbour, and a mile north the Murlough dunes — Ireland's first nature reserve — run down to a long strand.
Clough, down
Clough Castle is an Anglo-Norman motte-and-bailey beside the village of Clough in County Down, its 7.6m grassy mound topped by a ruined stone tower-house. It is free and open all year, with a short steep climb to views over the Lecale countryside towards Dundrum, Downpatrick and Slieve Croob.
Gilford, down
Gilford Castle is a grey-stone Scots Baronial house built in the 1860s for a partner in the Dunbar McMaster linen-thread firm, on a 200-acre demesne where the River Bann provides the fishing. It is a private estate rather than a visitor attraction, run for exclusive-use stays and events with no public tour or set hours.
Killyleagh, down
Killyleagh Castle claims to be one of the oldest inhabited castles in Ireland, with parts dating to around 1180, though its fairy-tale turrets are Victorian, added by Sir Charles Lanyon in the 1850s. Still home to the Hamilton family, it looks over a small harbour village on Strangford Lough. The gate lodges are let as self-catering stays.
Warrenpoint, down
Narrow Water Castle is a 1560s tower house and bawn built to guard the mouth of the Newry River where it opens into Carlingford Lough. The keep is a free state monument, open Friday to Sunday in summer; the Gothic-revival mansion behind it is a private Hall family home. It is a ten-minute stop with a long view to the Mourne Mountains.
Castle Street, down
Portaferry Castle is a 16th-century Savage tower house on the slope above the harbour, within sight of Strangford and Audley's castles across the lough. It's closed for structural repairs and won't open in 2026, so this is an exterior stop – but the tower, the ferry and the Exploris aquarium next door make it worth pausing.
Royal Hillsborough, down
Royal Hillsborough is the only settlement in Northern Ireland to hold a royal prefix, granted in 2021. Its centrepiece is Hillsborough Castle, the royal residence in the North, set in 100 acres of gardens where children go free. A free forest park with lakeside trails sits a short walk from the village square.
Newry, down
Rostrevor, down
Strangford, down
Quoile, down
Northern Ireland, down
Killinchy, down
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