Lough Ouler Hike Guide: Getting To The Heart Shaped Lake In Wicklow (AKA Tonlegee Hike)

One of my favourite things to do in Wicklow is to take a hike up Tonelagee to see Lough Ouler – Ireland’s heart shaped lake.

I’ve done the Lough Ouler hike twice over the years. The first was on a hike with friends on a dry and sunny day and everything went to plan.

The second was on a ‘wild camping’ weekend away and it was an absolute disaster (more on this another day…).

Below, you’ll find everything you need to know about one of the best hikes in Wicklow – the Tonlegee Mountain / Lough Ouler hike.

Some quick need-to-knows about the Lough Ouler Hike in Wicklow

Unlike the nearby Djouce Mountain walk and the many Glendalough walks, the Lough Ouler hike isn’t overly straightforward, if you don’t know what to look out for. Here’s some handy info:

1. Location

You’ll find Lough Ouler in the Wicklow Mountains, at the side of Tonelagee Mountain, the 33rd highest mountain in Ireland and the 3rd highest peak in the Wicklow Mountains (Luqnaquilla is the highest).

2. Home to the heart shaped lake in Wicklow

Yes, it’s on the Tonelagee hike that you’ll be treated to a view of the now-iconic heart shaped lake in Wicklow. On a clear day, there are few views in Ireland’s ‘Garden County’ that compare.

3. How long the hike takes

The Tonelagee hike routes we outline below each take between 2 and 3 hours to complete, depending on how long you stop to soak up the views. There’s also a Lough Ouler Loop that takes around 4.5 hours to complete.

4. Lough Ouler car park

The Lough Ouler car park I tend to park in is the one at Turlough Hill. It’s nice and big and the route to the top of Tonlegee Mountain is very straightforward from here. The other Lough Ouler car park is the one over at Glenmacnass Waterfall. I tend to avoid this one (info on why below).

Tonlegee Hike Route 1: From Turlough Hill

A group of us took this route for the first time a few years back as we were sick of doing the same Glendalough walking trails over and over again. 

Personally, I found it far safer than the route that starts from the car park at Glenmacnass (more on this below). While it’s not as straightforward as the Great Sugarloaf hike, it’s still hard to go amiss.

Parking

Whack ‘Turlough Hill Car Park’ into Google Maps. It’ll take you to the car park the fat red arrow above is pointing at. There’s a decent bit of space here, but make sure that to keep any valuables in the car hidden.

Getting to Lough Ouler

The path to the top of Tonlegee Mountain from here is usually straightforward, depending on the time of the year.

You’ll sometimes be able to see a trail to the top where people have been walking up and down. At other times of the year, it’s less obvious.

It gets steep from here

This stretch of the Tonelagee hike will get the blood flowing, as there’s a fairly solid incline that you’ll need to tackle.

When we last did this, it took us around 40 minutes to get from the car park to the top. When you reach level ground at the top of Tonlegee Mountain, whip out Google Maps again.

A tip for finding Lough Ouler

When we reached the summit of Tonlegee Mountain, we hadn’t a clue which way to go. So, in an attempt to avoid wandering aimlessly for ages, we whipped open Google Maps.

If you zoom in on your location, you’ll be able to see the shape of Lough Ouler very clearly. Make a beeline for it and the view below is what you’ll be greeted with.

I realise that this sounds a bit ridiculous, but it works! Just be careful as you walk as the ground is uneven and you’ll be walking near horizontal as you descend towards the lake.

Making your way back down

When you’ve finished soaking up the views, you need to return the same way. Just be careful as you descend, as it’s pretty steep.

Lough Ouler Hike Route 2: From Glenmacnass

The second Tonlegee hike route that takes you up to see the heart shaped lake in Wicklow starts from just past Glenmacnass Waterfall (or just before it, if you’re approaching from the Lough Tay side).

Now, I tend to avoid the climb from this side as you have to cross some very boggy ground that’s pretty hard to avoid. The trail is also hard to spot at the beginning.

However, if you fancy tackling the Lough Ouler hike from this side, here’s everything you need to know.

Parking

Your Lough Ouler car park for this route is located right next to Glenmacnass. This car park is isolated – leave nothing of value visible in the car.

The route to the lake

After leaving your car, head towards the trees and the river. You’ll see stepping stones that you can use to cross the river – be VERY careful here, as the stones are often VERY slippy.

Walk along the bank to the right and you’ll quickly reach the edge of the woods. Once you reach the edge, you may (emphasis on ‘may’) be able to find a path.

It can be difficult to spot (we struggled to find it when we were here in winter). When you find the path, start to climb. Keep going and you’ll see Tonelagee Mountain in the distance once you reach the top of the woods.

Some words of advice

Apparently, there’s an old road that runs along the top of the woods, but we didn’t see it when we were there a few years back.

If you find it, follow it to the right and you’ll find a path that’ll lead you up to Tonelagee Mountain. Take your time and enjoy the views out over Lough Ouler that you’ll be treated to on the way.

Making your way back down

When you finish up taking in the views of the lake, it’s time to make the return journey. From the summit of Tonelagee, follow the path north towards the Stoney Top (you’ll need to keep the lake on your right).

After a little while, you’ll see a standing stone with a cross on it. Take a right at the stone and make your way down from here. The lake will stay on your right.

FAQs about the Lough Ouler Walk

We’ve had a lot of questions over the years asking about everything from how long the Lough Ouler walk takes to where’s best to park.

In the section below, we’ve popped in the most FAQs that we’ve received. If you have a question that we haven’t tackled, ask away in the comments section below.

How long does the Lough Ouler hike take?

Allow around 3 hours for the Tonleegee hike. If you want to do the Lough Ouler Loop, allow around 4.5.

Where is the Lough Ouler car park?

You can park your car at the top of Glenmacnass Waterfall. If you’ve driven the Sally Gap and are driving towards Glenmacnass, you’ll see the car park to the right before you reach the waterfall.

Where do you start the Lough Ouler hike?

You can start the Tonlegee Hike from two places: The car park that’s right next to Glenmacnass Waterfall or the Turlough Hill car park (the other side of the mountain).

How do I get to Tonlegee Mountain without a car?

When we camped at Lough Ouler, we left the car at home and grabbed a taxi from the village of Roundwood. The taxi dropped us at Turlough Hill car park. We then followed a clear path to the top. From here, we worked our way down until the heart-shaped lake came into view.