Map & Elevation
About this Route
The Glen River path is the most popular and straightforward approach to Slieve Donard, Northern Ireland's highest summit at 850 metres. Starting from Donard Park in Newcastle, the route follows a well-maintained river path that climbs steadily through a scenic glen, crosses open moorland, then joins the iconic Mourne Wall for the final rocky ascent. The wall becomes your faithful companion all the way to the granite-strewn summit, where the views extend across the Irish Sea to Scotland, the Isle of Man, and south across the patchwork of County Down.
This is an out-and-back route covering 9.7 kilometres with 813 metres of ascent, making it a substantial half-day expedition. The lower glen section is gentle and forgiving, but once you reach the saddle between Donard and Commedagh, the final climb becomes steeper and rockier. The Mourne Wall itself is a remarkable piece of construction—built between 1904 and 1922 to enclose the water catchment area, it snakes across fifteen summits for 35 kilometres. On a clear day the summit is magnificent; in low cloud or high wind it becomes a serious mountain environment requiring proper navigation and clothing. The descent retraces your steps, though tired legs will find those river-path boulders a touch more troublesome on the way down.
The Mourne Wall is the finest mountain handrail in Ireland—a 19th-century lifeline that still guides walkers home when the mist rolls in.
TrailTrack
Route Waypoints
Start from the main car park in Newcastle. Pass through the gate into Donard Wood, following the obvious path that soon runs alongside the Glen River. The path is broad, well-surfaced and popular with families in the lower section.
The path climbs more persistently now, still following the tumbling river. Terrain becomes rockier underfoot with granite boulders and occasional stone steps. The enclosed glen opens up gradually with moorland slopes rising on either side.
Reach the broad col where the path meets the Mourne Wall. Turn left (south-west) and begin the steeper ascent alongside the wall. The final 400-metre climb to the summit is rocky, exposed and unrelenting, but the wall provides a handrail in poor visibility.
The highest point in Northern Ireland at 850 metres, marked by a large stone cairn and trig point beside the wall. The summit plateau is rocky and exposed. Allow time to take in the panorama before retracing your steps downhill.
Descend via the same route, taking care on the steep rocky section from the summit. The Glen River path can feel longer and more awkward on tired legs, so save some energy for the return journey.
Essential Tips
The Mournes are exposed to Atlantic weather systems and conditions can deteriorate rapidly. Even on a mild day at sea level, the summit can be cold, windy and shrouded in cloud. Carry full hillwalking kit including waterproofs, extra layers, hat and gloves regardless of the forecast. The Mourne Wall is a helpful navigational aid in mist, but a map and compass (or GPS) are essential.
The upper section from the saddle to the summit is steep, rocky and loose in places. Boots with ankle support and a good tread are strongly recommended—trainers are inadequate. Take your time on the descent; loose granite and tired legs are a recipe for twisted ankles.
Donard Park car park is pay-and-display and fills quickly on weekends and bank holidays, especially in summer. Arrive early to secure a space. Facilities are basic but there are public toilets at the car park. Newcastle town centre is a five-minute walk if you need supplies or refreshment afterwards.
The Glen River path is well-maintained but can be muddy after rain, and some sections involve stepping stones or minor water crossings. The upper moorland path is stonier and can be boggy in places. Gaiters are useful in wet conditions. The river itself is generally crossable, but can run fast after heavy rain—use common sense.