Glenmacnass Waterfall – an 80m cascade

Overview

Glenmacnass Waterfall drops 80 metres in three staggered steps at the head of the Glenmacnass Valley, in the Wicklow Mountains National Park. It’s a wide strip of silver more than a thundering plunge, and Frommer’s is fair to call it “more pretty than spectacular.” After a couple of days of rain it fills out and earns the stop; in a dry spell it’s a trickle over grey rock. If you only have a few minutes, the roadside view walking back towards Laragh is the one to have, and you barely need to leave the car.

The lip of the falls sits at about 350 metres above sea level; the base is around 270 metres. The water flows over smooth grey porphyritic granite, part of the Lugnaquilla pluton in the Leinster Granite Batholith, and darker schist of the Maulin Formation shows further down the valley on both sides. The valley itself is a textbook glaciated U-shape, with a moraine roughly halfway between the falls and Laragh marking where the ice front once stalled.

The name and the rock

The Irish name, Gleann Log an Easa, means “the glen of the hollow of the waterfall.” The Geological Survey of Ireland describes the valley as a fine example of a glaciated U-shaped trough, with over-steepened sides and a flat floor, cut when ice sheets ground through here during the last glaciation.

Seeing the falls, and the safety notice

There are two ways to look at Glenmacnass, and both mean paying attention to a fast, narrow mountain road.

From the roadside. The free car park sits at the top of the falls, on the left of the R115 driving south from Sally Gap. Follow the signposted path with care, but the best and safest view is from a short way back down the road towards Laragh, looking up the cascade. You’ll be on a winding road with no pavement, so walk against the traffic, stay tight to the edge, and keep children and dogs close.

From the car. Driving south towards Laragh, the falls are on your right, and there are a few pull-offs where you can stop for a photograph without getting out at all.

The warnings are not boilerplate. Do not climb the fence or wall at the top; the drop is severe. Do not pick your way down the wet river stones beside the car park to reach the base, where the rock is slick, the current strong, and there have been deaths. Break-ins have been reported at this remote car park, so leave nothing visible in the car. The park is under an orange fire warning in dry spells, so no naked flames.

Walking and wildlife

The car park is a starting point for some of the area’s best-known walks, including the popular route to the heart-shaped Lough Ouler and longer climbs onto Mullaghcleevaun (849 m) and Maulin Hill. Redstarts, meadow pipits and buzzards are about the valley; red deer graze the higher slopes, and otters and wild trout are in the river below.

Getting there

By car

From Dublin, take the M50 to the N11 south, then the R115 (Old Military Road) towards Roundwood. The drive is half the point, winding over sheep-grazed uplands and peat bog. The road was built between 1801 and 1809 so British forces could patrol the mountains after the 1798 rebellion; it’s now one of the most scenic routes in the country. The car park fills early on fine weekends.

Public transport

Limited, given how remote this is. St. Kevin’s Bus (route 181) runs from Dublin to Glendalough, from where you’d need a taxi. The Dublin–Rosslare line stops at Rathdrum (about 50 minutes from Heuston), then it’s a 25–30 minute taxi to the car park. The road is not one for casual cyclists or walkers.

Nearby

• Sally Gap – the mountain crossroads at the top of the Old Military Road, with the Lough Tay drive off it.
• Lough Ouler – the heart-shaped lake on the flank of Tonelagee.
• Glendalough – St Kevin’s monastic valley, 9.5km south, with its round tower and walking trails.
• Avoca Handweaving Mill – a working woollen mill down in the Avoca Valley.

Practical information

Come after rain and go early, both for the water and for a space in the car park, and take your view from the roadside rather than the rocks.