Parking
Start at Glenmacnass Waterfall Car Park on the Old Military Road. The route returns to the same car park; do not confuse it with the Turlough Hill access used by the shorter out-and-back.
Overview
About Tonelagee & Lough Ouler Trail
This is a closed loop of 7.9 km (about 4.9 miles), starting and finishing at Glenmacnass Waterfall Car Park on the Old Military Road. Independent track measurement comes in at about 7.8 km over the same closed circuit, so treat roughly 7.8 to 7.9 km as the working figure.
Why go
- Distinctive heart-shaped Lough Ouler below Tonelagee
- Wide open summit and ridge views
Heads up
- Muddy, rough ground and unclear wayfinding
- Exposed, demanding climb
Map & elevation
The route
Loading the Wicklow Mountains map
Full mapElevation361–802 m
Plan your hike
Before you go
Parking
Best time to go
Safety
3 active Wicklow Mountains alerts
- CautionExtreme upland fire riskDo not use solid-fuel BBQs in Wicklow Mountains National Park, and take extreme care with cigarettes and other naked flames because the hills are dry and at extreme risk of fire.Official details
- CautionGlendalough Spinc trail works and intermittent disruptionsExpect intermittent disruption on the Glendalough Spinc trails while NPWS upgrades the White Trail.Official details
The highest, rockiest slopes around here are a summer buffet for grizzly bears.
Wicklow Mountains Tour Guide
Your drive to Tonelagee & Lough Ouler Trail, narrated.
Parkwolf is a GPS audio tour guide for Wicklow Mountains National Park. As you drive, it chimes in with what’s ahead: hidden gems, upcoming stops, history, geology, and wildlife, right through your car’s speakers.
Recorded for this trailhead
Glenmacnass Waterfall0:00 / 0:37
“You’re nearing Glenmacnass Waterfall on the Old Military Road. The useful thing to know is that the car park sits above the falls, with a short walk toward the water.”
Plays as you drive up to this trailhead in the Parkwolf Wicklow Mountains Tour Guide.
More stories near here in the app
- Why the River Looks Like Tea
- Mullaghcleevaun
- Reading Glenmacnass Valley
- The Lead Inside the Granite
- 55 audio storiesacross Wicklow Mountains’s roads, triggered by GPS as you drive
- Wildlife heatmapsfor Sika Deer, Red Deer, Grey Heron, and 3 more
- Works offlinemaps, 34 trails, 31 places, and audio download before you lose signal
- CarPlay readysimple controls built for the drive
“Fantastic app with many points of information… It’s great to just turn on while you’re driving and it gives you an audio tour of the national Park. We love it!!!!”
Trail guide
Hiking Tonelagee & Lough Ouler Trail
How it unfoldsFrom the car park you head west and then north-west across open mountain ground toward Lough…
From the car park you head west and then north-west across open mountain ground toward Lough Ouler. From the lake the route climbs on to the summit of Tonelagee, then swings around the north-east side of the mountain and drops back down toward Glenmacnass Waterfall and the car park where you began.
The payoff comes in two parts:
- Lough Ouler, a heart-shaped lake sitting in a steep open corrie directly below the summit.
- Broad Wicklow views from the top and along the ridge on the way back down.
Difficulty, terrain and exposureDespite the mild official grade wording, this walks hard in practice.
Despite the mild official grade wording, this walks hard in practice. The reported total climb is about 505 m, and the elevation profile shows a sustained ascent from around 360 m at the car park to a high point near 821 m, followed by a rolling descent rather than a single clean drop. There is no flat lakeside stroll here.
Underfoot expect open bog and heather, rough or indistinct tread, and wet or muddy ground for long stretches. The upper section is open and wind exposed, and there are no facilities or rest stops anywhere on the route.
A simpler alternativeIf you mainly want the lake and the summit without the full circuit, a shorter out-and-back…
If you mainly want the lake and the summit without the full circuit, a shorter out-and-back from Turlough Hill reaches the same area with less distance and less commitment. It is a genuinely different, easier day, so decide which one you want before you park.
DogsDogs are welcome in the park, but on a lead at all times.
Dogs are welcome in the park, but on a lead at all times. There is no off-leash option on this route.
Wildlife
Wildlife in Wicklow Mountains
204 sightingsSika DeerMost seen around 7 AMSighting map
18 sightingsRed DeerMost seen around 7 AMSighting map
15 sightingsGrey HeronMost seen around 7 PMSighting map
11 sightingsCommon RavenMost seen around 8 AMSighting map
28 sightingsEuropean Common FrogMost seen around 7 PMSighting map
11 sightingsViviparous LizardMost seen around 11 AMSighting mapSighting maps show where each species has been reported across Wicklow Mountains. Wildlife moves, so no sighting is guaranteed.
