The Mourne Mountains, usually just referred to as "The Mournes", are the highest peaks of Northern Ireland. They are dramatic and form the background to the south of County Down. Closer to Newcastle they are brooding giants. Past Annalong a very distinctive stone wall landscape exists.
The Mourne Mountains were formed by volcanic activity 66 million years ago in the Mesozoic Era. This activity didn't break surface as erupting volcanoes, so you don't see spiky peaks or basalt columns; rather it was an upwelling of magma beneath the Silurian sandstone, shale and mudstone that cloaks County Down further north. Glaciers during several Ice Ages wore away the upper layers until the granite was exposed - this is very hard-wearing so the Mournes weathered less than other Irish mountain ranges, and have the highest peaks in Northern Ireland. The glaciers carved out the U-shaped Silent Valley and left vast boulders teetering on the slopes. Prehistoric dwellers used the stone for their sturdy monuments, exporting it as far as the Brú na Bóinne complex near Drogheda, and shifting it off their fields into drystone walls. The granite was quarried for building stone from prehistory to the present day. Further north around Slieve Croob is a very much older crop of granite, then in the lowlands towards Downpatrick are drumlins, hillocks of gravel deposited beneath the glaciers, forming islands where they meet the sea at Strangford Lough.
West of the Mournes is a long broad valley then the mountains of the Ring of Gullion, a collapsed volcanic caldera. It's probably older than the Mournes; it's arguably less scenic. To the south is Carlingford Lough, the only fjord on Ireland's east coast, separating County Down from the Republic. Those areas are described under Newry and aren't considered further here.
The mountains draw the cloud and rain, so the peaks get 2000 mm annual rainfall, while the coast averages 1300 mm and Murlough is in a "rain shadow" with only 750 mm. The terrain is therefore distinctly soggy, and reservoirs catch the rainfall for Belfast's water supply. Potatoes are grown on the low ground, cattle graze the grassy gentler slopes, and sheep munch away right up to the summits, wherever they're not impeded by the Mourne Wall. The highest peaks, clad in heather and gorse, are towards Newcastle: Slieve Donard is highest at 850 m but most of the Mournes are in the 500-650 m range, with some 70 lesser hills of 300-400 m. So they're a good Saturday afternoon hike but don't demand technical mountaineering, and they're also very accessible from the cities.
They were not always so accessible: they were spoken of as an island, which they look like from afar, and until the road around the coast was built in the 19th century, you could only reach places such as Kilkeel and Annalong by boat. The villages had fishing fleets, and shipped out granite to pave the streets of Victorian Britain. So much for the legitimate trade - the Brandy Pad trail was a mountain route for contraband, and perhaps for a few wanted men. Defeated Jacobites after the Battle of the Boyne laid low in the hills and practised small-scale resistance, until the militias and courtrooms at Banbridge crushed them.
There is still quarrying and gravel extraction in the area but it's small scale, and the main industries are farming, forestry, fishing, and of course tourism. Thus, it's a managed, farmed, inhabited landscape and not a wilderness. In 1966 the Mournes were designated as an Area of Outstanding Natural Beauty (AONB), and in 1986 this was extended to include Slieve Croob and the nearby farmlands and coastline. (It doesn't include Ring of Gullion or Strangford Lough, which are separately designated.) Carlingford Lough is a RAMSAR site, Murlough and Rostrevor Wood are National Nature Reserves, and there are many SSSIs - sites of special scientific interest. The National Trust owns large tracts of the Mournes. There were moves in the early 21st century to designate the area as a National Park, but this was rebuffed by residents and local councillors who feared ceding control to a distant, less democratic body. One problem had been the multiple local authorities with a stake in the area, but this was resolved by the reorganisation of 2015 which brought the whole area within Newry, Mourne and Down District. There are no park fees, permits or gates to enter the Mournes, you simply pay for individual amenities such as parking.
- 1 Newcastle is the main base for exploring the area.
- 2 Annalong has a 19th century corn mill. A lane leads inland to Silent Valley.
- 3 Kilkeel is a fishing village. It has accommodation.
- 4 Warrenpoint straggles east into Rostrevor. Both have accommodation and eating places.
- 5 Newry also has access to the Ring of Gullion further west.
There are regular buses from Belfast Europa station to Newcastle, and to Newry continuing to Dublin airport and city. The Belfast-Dublin trains also stop in Newry.
A less frequent bus runs cross-country from Newry to Newcastle and Downpatrick.
An hourly bus runs from Newry to Warrenpoint, Rostrevor and Kilkeel, and another bus runs every couple of hours between Kilkeel and Newcastle. On M, W, F a bus makes two runs from Kilkeel up to Attical at the entrance to Silent Valley.
So it is possible to reach all the area's towns by public transport, and to circle the mountains, but altogether it's much easier by car. (On fine weekends, what feels like half the population of Belfast will drive here to demonstrate this point.) You'll also need a car to reach the start of the various hikes.
1 Carlingford Ferry plies across the opening of the lough between Greencastle in County Down and Greenore in the Republic east of Dundalk. See Newry#Get in for details, but in autumn 2020 the ferry is suspended.
You'll need a car. The Rambler bus no longer runs.
- Mourne Wall courses for almost 20 miles across the mountains surrounding Silent Valley reservoir, which supplies Belfast. It was built 1904-22 to keep sheep and cattle, and especially their productive rear ends, away from the reservoir and its water catchment. It's a drystone wall made of local granite and is about 5 ft high and 3 ft thick. It crosses 15 mountain summits including Slieve Donard, and one grueling challenge is to hike the length of it in a single day.
- The Invisible Tree: the Atlantic regions of Europe used to be carpeted with oak forest, and one surviving area is at Rostrevor on the south coast. A 200 year-old oak stands at the entrance to the forest park, but when an environmental assessment team arrived to gauge the effect of a nearby proposed development, they studiously avoided seeing or recording it. In 2019 the Woodland Trust made a cause of this, protesting that the assessors were willfully blind to the impact of developments. But to be fair, it wasn't the tree that was paying the assessors.
- Prehistoric sites are dotted all over. The most imposing is Legananny Dolmen, a great stone tripod near Castlewellan. Many are low-lying and frankly look like garden decorations, such as Slidderyford Dolmen near Newcastle, or Kilfeaghan Dolmen between Rostrevor and Kilkeel.
- 1 Slieve Donard is Northern Ireland's highest mountain at 850 m / 2790 ft, so it ranks as a Marilyn. It's climbed by a straightforward but muddy and eroded path from Newcastle. Park at Donard Forest and ascend through mixed woodland along Glen River. The riverbank becomes steep, almost overhanging, so there's a bit of a scramble; you criss-cross the river but there are footbridges. You emerge onto heathland and reach the saddle or col, where you fetch up against Mourne Wall. Turn left (southeast) and follow the wall up past a couple of false summits to the top. There are two prehistoric burial cairns at the summit, but they're in poor shape, just a jumble of stones. The route is 3 miles each way, reckon 4 hours there and back.
- Bloody Bridge is the start of a longer but more scenic route. From the car park on A2 south of Newcastle, head west up the glen - the Brandy Pad smugglers' path - to reach the south shoulder of Slieve Donard. Either head straight up along the wall (the view is better on its west flank) or continue northwest to the saddle.
- Millstone Mountain by the Granite Trail: see Newcastle for this steep but simple walk.
- 2 Slieve Commedagh is Northern Ireland's second highest at 767 m / 2516 ft. Follow the same route up Glen River but turn right (northwest) at the saddle and wall. Ascend steeply to a false summit, then right (northeast) to the true summit. You could continue back to town along the rim of the cwm and Shan Slieve then down the steep ridge to rejoin Glen River. Or return to the wall and make a circuit of Slieve Corragh, Slievenaglogh, descend to Diamond Rocks then on lower ground back to the saddle and Glen River path. Diamond Rocks can also be reached from the north up Shimna River valley.
- 3 Slieve Binnian is the third highest at 747 m / 2451 ft. It's more scenic, as it looks down on the Silent Valley. It's done as a triangular walk of 7 miles from Carrick Little car park above Annalong. Head west straight up the obvious summit. Then pick your way north along the ridge to the North Tor and descend to the saddle overlooking Ben Crom reservoir, before turning southeast downhill past Blue Lough to the car park.
- Silent Valley can be reached from the south without humping over the mountains. Park up and follow the firm track, which continues up to Ben Crom reservoir.
- 4 Slieve Bearnagh at 739 m / 2425 ft is double-peaked. You could reach it via the Glen River route, or up Shimna valley. It's usually combined with Mealmore (704 m). A switchback ridge descends south towards the village of Attical.
- 5 Hen, Cock and Pigeon are a good example of the mountains further west. They're lower but steep, with good views and popular for rock climbing. Access from the car park along Sandbank Rd east of Hilltown, for a six mile circuit.
- 6 Slieve Croob at 534 m / 1754 ft is the centre of the Dromora Hills, north of Newcastle and detached from the Mourne Mountains. There's a firm track to the radio mast at the summit so it's an easy walk.
- The Coastal Trail (A2) is more of a driving route. For walking, the best sections are around Bloody Bridge, Annalong and Kilkeel.
- Sing The Mountains of Mourne, not necessarily while on top of them. In this music-hall song, written by Percy French in 1896, our hero in London contrasts the artificiality of his surroundings (especially the women) with the natural charm of the mountains sweeping down to the sea, and of his own dear Mary "the wild rose that's waiting for me". He hopes.
Standard advice on suitable clothing and footwear for the hills. But they're of no great altitude and your main hazard is road traffic.
The towns all have a mobile and 4G signal, but there are lots of dead areas beyond, even on the approach highways. Don't be relying on a mobile up in the hills.
- Lecale Peninsula east of Newcastle has a scenic coastline.
- Strangford Lough, almost pinched off from the sea by Ards Peninsula, forms an Area of Outstanding Natural Beauty together with Lecale Peninsula.
- Ring of Gullion rises west of Newry.