Castlewellan Forest Park – Slievenaslat Walk
This steep climb through the forest provides a series of viewpoints offering panoramic views of the Mourne Mountains and surrounding drumlin landscape of Co Down.

County Down
Distance 2.2 miles
OS Map Sheet 29
Terrain Strenuous including steep climbs
Nearest Town Castlewellan
Route Shape Circular
Grid Reference J335364
Route Type Forest, Hill, Lakeland, Woodland
Part of the new Castlewellan Walking Trails launched in November 2014, this trail is signposted from the Lakeside car park – follow the yellow waymarkers.
The most strenuous walk in the Park, this trail is rocky in places with numerous steps both up and down. As such it is suitable for those with a higher level of fitness and stamina.
Starting at the Lakeside Car Park, follow the north side of the lake before starting the steep climb to the summit of Slievenaslat (272 metres). Openings within the forest and the summit itself provide panoramic views of the Mourne Mountains and the drumlin landscape of Co.Down before commencing your descent.
This is a ‘Strenuous’ trail suitable for those with a high level of fitness and stamina. Extremley variable and uneven surface including large loose material including rocks and roots. It includes long steep climbs and descents.
This walk is situated in a working forest environment and may be subject to diversion and closure from time to time.
Up to date information is available on the Forest Service web site.
Views of the Mourne Mountains, Castlewellan Castle, lake and gardens
From Castlewellan the forest is signposted from Main Street.
Translink – journeyplanner.translink.co.uk
Car park (fee charged), café, toilets (disabled access), picnic areas, The Peace Maze, Activity Centre, lecture room/ classroom, camping & caravaning, orienteering route, mountain bike trails. The following facilities are available for users with limited mobility: – Café (wheelchair accessible) – Disabled toilets – Disabled parking.
Grade 5
- There may not be a formalised path, and variable, single file trails are to be expected.
- Gradients and cross slope could be expected to be steep and not limited.
- Obstacles and surface breaks of greater than 75mm measured across the line of the path to be expected.
- Overhanging branches are possible. Passing places and rest areas may not be formalised or provided.
Comments will be reviewed and those that cause offence will be removed. This is at the discretion of WalkNI.
We want everyone to be able to enjoy the walking routes listed on WalkNI safely and easily.
If you have come across any problems whilst walking a route, please let us so we can pass on any issues to the appropriate management body responsible for maintaining the walk.
Walk Route
Castlewellan Forest Park – Slievenaslat Walk
There is quite a strenuous walk up to the summit of Slievenaslat mountain and it is not suitable for those with mobility issues.
On a good day the views from the summit and another viewpoint are worth the effort.
The only downside is the large number of mountain bikers, some of whom don’t seem to care about walkers in the parts where the mountain bike and pedestrian trails cross.
Haven’t walked to Slievenaslat for about 20 years, but the view over the Mournes and Dundrum Bay has always been spectacular and worth the effort. Thoroughly enjoyable.
A hidden gem with one of the best views of the Mournes I’ve seen – well worth the climb! The stone steps descending from the viewpoint added an interesting element to the route. I can’t recommend enough.