Overview
Mullacor is not a mountain most people climb for its own sake. At 661 m (2,169 ft) it is the high point of the broad horseshoe of ridges that wraps around the Upper Lake of Glendalough, and it tends to get bagged in passing: on the long Spinc and Lugduff circuit, on the shorter loops out of Glenmalure, or on the Wicklow Way, which crosses its saddle at around 550 m. The name is Mullaigh Mhór, ‘big hilltop’, which about covers it. There is a summit cairn, a boggy plateau, and a view down into Glenmalure and across to Turlough Hill and Lugduff that makes the pull worthwhile.
For the record, it is listed as a Hewitt, an Arderin and a Vandeleur-Lynam, and with a prominence of 102 m it ranks 90th on MountainViews’ 100 Highest Irish Mountains. It shares the horseshoe with Lugduff, Conavalla, Turlough Hill and Camaderry.
Landscape and geology
The rock underfoot is dark blue-grey slate, phyllite and schist, not the quartzite of some Wicklow tops, and the last Ice Age did the shaping – grinding out the ridges and scattering the erratics that still litter the slopes. This is open, exposed ground once you leave the forestry: heath and rough grass up to a summit that holds water. Red deer range the area, and local lore keeps a white deer among them. The Derrybawn woodland trail (the Orange Route) is one way up through the trees before the ridge opens out.
Walking routes
Mullacor is approached on foot from Glendalough or Glenmalure, and the terrain shifts fast from forest track to windswept heath, so conditions change with the season and the weather.
- Mullacor, Lugduff and the Spinc – the classic round, roughly 15 km and the better part of a day. It links three tops and crosses the exposed Spinc boardwalk above the Upper Lake. It wants good fitness, sure feet and a head for the steeper, rockier ground.
- Mullacor loop from Glenmalure – shorter, about 10 km, with a gentler ascent through forestry and moorland before the summit.
- Via Derrybawn from Glendalough – climbs the wooded flank of Derrybawn Mountain and finishes on Mullacor, giving the lake views without the exposure of the full ridge.
Whichever you take, the last pull to the cairn crosses a wet, mossy plateau that turns to bog after rain, so boots with real grip earn their keep. Cloud drops quickly here in summer and ice lingers in winter, so carry a map and compass or GPS and know how to use them. This is not ground for wheelchairs or buggies.
Practical information
Mullacor sits inside the Wicklow Mountains National Park, open year-round with free access, no ticket and no facilities on the hill.
Getting there and parking – trailhead parking near Mullacor is limited, and the Upper Lake car park at Glendalough charges a fee and fills by mid-morning on a fine weekend. The free Laragh car park beside the Woollen Mills is the better bet; it is open daily 8am–8pm. Either way, arrive before 10am in summer.
Public transport – a Local Link service (route 183) runs from Wicklow town toward Glendalough, and seasonal coach services run from Dublin. Timetables change, so check before you plan a day around them.
Dogs and wildlife – dogs are welcome but should be kept on a lead near stock and where ground-nesting birds may be about. Stay on the paths to spare the vegetation.
When to go – summer gives the longest daylight and the driest ground; winter demands full mountain kit and the experience to use it in snow or ice.
Nearby
If the legs have anything left, the Upper Lake of Glendalough sits below the trailheads and mirrors the peaks on a still morning; the monastic city beside it keeps its round tower and early medieval ruins. For a softer afternoon, Avondale Forest Park has easy woodland trails and Avondale House, birthplace of Charles Stewart Parnell, a short drive off.
Park at the free Laragh car park rather than the pay-and-fill Upper Lake one, start early, and treat Mullacor as one top on a bigger round rather than a destination in itself. Check the Met Éireann forecast first: Wicklow weather turns regardless of the season.