Overview
Prince William’s Seat and its neighbour Knocknagun are both exactly 555 metres (1,821ft), separated by a shallow col on the northern rim of the Glencree valley, right on the boundary between County Wicklow and County Dublin. Both sit within the Wicklow Mountains National Park. Prince William’s Seat is the 296th-highest of Ireland’s Arderin summits (peaks over 500m with at least 30m of prominence); its 63m of prominence is not enough to make the Vandeleur-Lynam list. For all its modest height, it draws steady foot traffic, thanks to its closeness to the capital, well-kept forest tracks and a summit view that reaches across Dublin Bay to the coastal headlands.
The walk
The standard route is a 10.5km circular walk of about three to four hours. It starts at the Curtlestown Wood car park near Boranaraltry Bridge, off the Glencree Road. From there the path climbs steadily through a dense plantation of Scots pine and spruce, following the yellow signposts of the Wicklow Way, Ireland’s first waymarked long-distance trail, which runs 131km from Marlay Park in Dublin to Clonegal in County Carlow.
After roughly 3km the tree line gives way to open, heather-covered slopes, and the broad forest tracks narrow to grassy footpaths as you reach the saddle between Prince William’s Seat and Knocknagun. The final push to the trig pillar crosses boggy ground and loose granite scree.
At the top, the concrete triangulation pillar – likely a relic of the 1960s retriangulation of Ireland rather than the original 1830s survey – makes a clear landmark and a natural rest. On a clear day the view takes in:
- the conical Great and Little Sugar Loaf and Bray Head to the east
- the Dublin city skyline and the sweep of Dublin Bay
- the higher Wicklow peaks, including Kippure and the Tonduffs, to the south
- the far horizon of the Irish Sea
The return leg drops gently back into the forest, looping through quieter woodland tracks before rejoining the road.
History and naming
The royal name is usually put down to Prince William, brother of King George IV, after a visit to Ireland in 1821. But placename research by the Irish academic Paul Tempan suggests it may have been assigned later by Ordnance Survey surveyors in the 1830s, possibly muddled with a neighbouring landmark.
Just over a kilometre west sits Knocknagun (Irish: Cnoc na gCon, ‘hill of the hounds’). Near its summit stands a great granite tor known locally as Fitzwilliam’s Seat – a resting place for the hunting parties of the Fitzwilliam family, who owned the surrounding land from the mid-16th to the late-17th century, and a name still recorded in the area in 1939. Some historians reckon the surveyors swapped ‘Fitzwilliam’ for ‘Prince William’ when they mapped the adjacent, slightly sharper peak. The mountain sits in the townland of Glencullen Mountain (Sliabh Ghleann Cuilinn), a reminder of a landscape shaped by both aristocratic estates and centuries of hill farming.
Through the seasons
The mountain changes noticeably with the year. Spring brings pink foxgloves and purple heather across the upper slopes, while early summer adds bilberry and gorse, whose yellow flowers carry a faint coconut scent. Autumn turns the bracken and heather russet and gold, which makes the forest descent particularly good. Winter walks are possible, but the exposed summit ridge can be icy and the boggy saddle between the two peaks turns treacherous in a freeze.
Practical information
- Parking and access: free parking at the Curtlestown Wood car park near Boranaraltry Bridge, with plenty of room for cars and small vans.
- Public transport: there’s no realistic public transport to the trailhead – the car park is only sensibly reached by car.
- Dogs: well-behaved dogs are welcome, on a lead near the forest car park and under close control on the open slopes, where ground-nesting birds and livestock may be about.
- Accessibility and terrain: uneven ground, rocky sections and moderate gradients mean it is not suitable for wheelchairs, pushchairs or standard strollers. Hiking boots with good grip are essential, especially after rain when the grass and the saddle near Knocknagun turn slick and boggy.
- Navigation: the path is clearly marked with yellow Wicklow Way signposts and follows forest tracks for most of the ascent, but carry a map or a downloaded GPX file, as visibility can drop quickly in mist.
- Facilities: no toilets, cafés or shelters on the summit; the forest car park has basic litter bins. Bring water, food and a waterproof layer.
- Nearby walks: the same car park is the start for shorter, family-friendly forest loops in Curtlestown Wood, and Powerscourt Estate, Powerscourt Waterfall and the Ski Club of Ireland are all a short drive away.
- Afterwards: a short stroll into Glencullen village brings you to Johnny Fox’s, which bills itself as one of the highest pubs in Ireland, with traditional meals and regular live music.
Pick a clear day. In mist the summit is just a concrete pillar in grey soup, and the Dublin Bay view that makes the climb worth it disappears entirely.