17 November 2024.
Planning your visit to Lac d’Oô? This guide has you covered with everything you need to know.
Framed in vertical emerald cliffs that gush with cascades, the deep, midnight blue pool of Lac d’Oô is like something out of a fairytale.
But it is the powerful, single-drop waterfall of Cascade d’Oô, a gleaming veil that tumbles over its southern precipice, which steals focus and adds even more to the magic.
Whether intentional or not, the lake’s name certainly seems to be an onomatopoeic representation for the sound awestruck visitors emit when they first lay eyes on this captivating scene, though it is more commonly attributed to the historic word for water of which the region has in abundance.
In an effort to break up the journey between the Ariège Pyrenees and the Pyrenees National Park, I stumbled upon the lovely walk to the Lac d’Oô.
Despite being an artificial lake, the scenery here is simply beautiful and the trail is an excellent choice for a short and easy walk between these two regions.
For those with more time to spare, Lac d’Oô also provides access to Lac d’Espingo and Lac Saussat located higher up the valley, or Lac du Portillon which lies concealed between the austere peaks of the high alpine plateau and provides endless opportunities for experienced hikers to explore.
It’s worth keeping in mind that this is one of the most popular spots in the French Pyrenees and does get particularly busy, even outside the peak summer months, so don’t expect to have the place to yourself.
Things do quiet down beyond Lac d’Espingo, but hitting the trail early is the best way to beat the crowds.
Distance | 6.4 km return
Duration | 2 hours
Elevation | 1,149 m to 1,527 m (378 m gain)
Difficulty | Easy
Trailhead | Parking Granges d’Astau
Sandwiched between the Pyrenees National Park and the Ariège Pyrenees, Lac d’Oô is located in the tiny section of the central Pyrenees that falls within the Haute-Garonne department.
The closest town of Bagnères-de-Luchon is located 15 minutes from the small commune of Oô and the verdant Val d’Astau which plays host to the lake.
The closest major city to Lac d’Oô is Toulouse which lies around 2 hours away. Take the A64 southwest past Saint-Gaudens and turn onto the N125/D125 through the Garonne and Pique Valleys towards Bagnères-de-Luchon.
From here, a meandering country road guides you west, past several charming blink-and-you’ll-miss-it mountain villages, before turning onto the D76 through the Val d’Astau.
Follow this for 6 km until the very end where you’ll arrive at Les Granges d’Astau (the Astau Barns) and a large, busy parking area.
At the end of the paved section, the road forks into several avenues with free parking bays, or you can continue all the way to the end where there is a gravel patch that offers additional space.
You’ll also find two restaurants here and a hiker’s hostel.
If you’re arriving from the west, Oô is located around 1.5 to 2 hours from Tarbes or Pau via the A64. Turn into the Neste Valley towards Arreau and then follow the D618 until the turnoff for the lake.
However, if you’re coming from this direction, I’d highly recommend taking the slower but more scenic detour via the beautiful Ardour Valley and over the spectacular Col d’Aspin which will add about half an hour to the trip.
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FIND YOUR RENTAL CAR // Both Pau and Toulouse have several options for car rental from either the train station or airport. Public transport is basically non-existent in this region of the Pyrenees so visiting with your own vehicle is the best way to explore.
For this trip I used and would recommend Discover Cars who offered by far the most competitive rates for the region. Find the best deals here.
Unfortunately, there is no public transport to Oô. The closest option would be to travel to Bagnères-de-Luchon which takes around 2.5 hours and would leave you 14 km short of the trailhead.
From either Pau or Toulouse, take the TER ‘Pau-Toulouse’ train line to Montréjeau and transfer to a service bound for Gare de Luchon. See transport options here.
Though I personally didn’t stay in the vicinity of Lac d’Oô and instead used it as a stop over on my way between Seix (for the trail to Cascade d’Ars) and Cauterets (for the hike to Lac de Gaube), Bagnères-de-Luchon would make an ideal base for those keen to stay nearby.
Most accommodation options in town are in the form of private apartments, though there are also a handful of cosy hotels in the area.
Hikers keen to stay in the mountains will also find three well-placed refuges in the area.
Hôtel La Rencluse | This charming mountain hotel is the best rated option in Bagnères-de-Luchon and provides a warm welcome and cosy rooms with a lovely outlook up the valley. Guests also love the homemade breakfast spread which highlights local produce of the region. Check rates and availability here.
L’Auberge d’Astau | Located right at the trailhead, this lodge is a popular budget choice for hikers passing through the area. Both private rooms and dormitories are available, with the option to include breakfast and dinner. Open during peak season only.
For those planning a multi-day hiking itinerary, other refuges that can be reached within a day of walking include: Refuge du Lac d’Oô, Refuge d’Espingo and Refuge du Portillon. Most operate only through summer and fall along the GR10 route.
From the large parking area, navigate past the L’Auberge d’Astau and the two restaurants and onto the gravel road where the route begins.
As part of the popular GR10 trail, the entire route is well-marked and well-trodden and you really can’t go wrong on the way to the lake.
Feeding out from Granges d’Astau, cows freckle the lush pastures and the swollen river meanders through the vast valley floor flanked by the steep forested walls of the Val d’Astau.
My visit was preceded by days of heavy rainfall and the signs were everywhere.
The white thread of Cascade Chevelure de la Madeleine peaking through the trees, small waterfalls gurgling beside the route, puddles puncturing the path and, in some areas, the trail itself was transformed into a river.
However, the first indication was the crossing of Ruisseau de Médassoles which lies a short way beyond the carpark.
Usually, this is a smallish stream which cuts across the gravel road and can easily be crossed in one long stride, yet after so much rain it was now a shallow several metre wide torrent across the road where the only way across was through.
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TOP TIP | Ordinarily, I would suggest running shoes were perfectly adequate for this hike as there’s no particularly challenging terrain if you’re only going as far as the first lake. However, if you are visiting after heavy rainfall, there will be a few very wet sections to contend with so solid waterproof hiking boots are a good idea.
Onwards, the trail climbs very gradually along the left bank of the valley and enters the forest which thankfully provides some shelter from the blazing sun for the majority of the hike.
After 1.4 km, the path crosses a small stream cascading amongst the trees and you’ll arrive at a cleared tract of forest which offers up beautiful views straight down the valley.
For the next kilometre, the way climbs more steeply on a wide rocky path via a set of tight switchbacks.
During my visit, this section was basically a river of its own and, while I saw many hikers doing a dance of tentative hops and lunges between the rocks in an effort to keep their shoes dry, there was really no way to avoid getting a little wet.
Pushing on, the trail flattens out and the roar of the river surging over the dam wall is unmistakable.
After a further 500 m, the path emerges from the trees on a narrow path beside a charming stone bridge which carries you over the churning Neste d’Oô.
Originating from Lac du Portillon nestled beneath the colossal Perdiguero massif, this river is fed by snowmelt trickling down from these rugged high alpine peaks and in turn feeds all but one of the area’s lakes.
From the bridge, you’ll catch your first glimpse of the powerful Cascade d’Oô hurtling over the precipice above the violent overflow spilling from dam.
Cross over to the right bank of the river and climb the hill to reach the refuge and the spectacular setting of Lac d’Oô.
The perfect pyramid of Grand Quayrat pierces the sky, steep forested cliffs fringe the deep navy pool and countless ribbons of water cascade across the vertical walls, though they are feeble support acts to the majestic waterfall that takes centre stage.
Tumbling 275 m in a single drop, the impressive Cascade d’Oô is the indisputable star of what is already a remarkable picture-perfect scene.
The northern shore of the lake is framed with a wide swath of grass which makes an ideal spot to enjoy a picnic lunch while admiring the view.
The Refuge du Lac d’Oô also serves hot and cold drinks and snacks for those who might need a pick-me-up.
Otherwise, if this is as far as you’re walking, simply return back to the parking at Granges d’Astau via the same trail.
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TOP TIP | Visiting in spring or after heavy rainfall when the river is at its fullest will ensure the falls are also at their best.
Unfortunately, I had to turn back at this point, but for those keen to continue into the mountains, you have several options to extend your hike, either continuing to Lac d’Espingo and Lac Saussat, or further to Lac du Portillon for more experienced hikers.
For those seeking a multi-day hike, Refuge du Portillon provides access to a variety of trails that traverse the rugged plateau or cross the border into Spain.
The most popular option is to push on to Lac d’Espingo located on the shelf above Lac d’Oô, a further 3km up the valley.
Completing the full out and back trail to Lac d’Espingo is a 12.4 km / 4.5 hours hike, with 846 m elevation gain.
First, you’ll need to backtrack to the bridge and cross to the opposite bank.
From here, the trail circles around the left side of the lake, weaving in and out of the forest, passing several small streams and climbing a number of switchbacks and twisting sections of trail to reach the upper valley and the final ascent to Col d’Espingo at 1,973 m.
With a similarly beautiful setting, the Refuge d’Espingo perched on a hill above the lake makes another decent spot for a break.
Those after a more challenging full-day hike can push on to Lac du Portillon which sits at 2,580 m and will bring you into the rockier terrain of the high alpine plateau.
Just 700 m from Espingo, you’ll reach a metal bridge over the Neste d’Oô and arrive at the shores of Lac Saussat.
The climb continues past the small pool of Coume de l’Abesque and up the zigzagging trail that leads towards the upper shelf where large boulders and rock slabs dominate the landscape.
Streaked in snow and rust-red veins of rock, austere peaks tower above the southern shores of Lac du Portillon, forming the natural border with Spain and another spectacular backdrop.
Similar to Lac d’Oô, the north bank is also bordered by a dam wall.
From Refuge d’Espingo, it’s a further 5 km to the lake’s Refuge du Portillon, with an additional 660 m of elevation gain. The full trail is 11 km / 4.5 hours one way and is possible as one long day hike, though more popular is to stay overnight.
At the trailhead you’ll find two restaurants serving up meals, snacks and drinks. Both are open and thriving during the peak summer season though do wind down operations in the lead up to winter. Reservations are advised during summer and on weekends.
For those planning to self cater, there are several supermarkets and bakeries in Bagnères-de-Luchon, as well as the popular Marchè de Luchon where you can find local produce from across the region.
However, it was so busy during my visit that parking in town was an absolute nightmare so keep this in mind if you’re travelling during peak season or on weekends.
Unless you’re staying in town, I’d recommend instead going to the large Intermarché on the outskirts, or at the roundabout in Cierp-Gaud for those arriving from the east.
Near the restaurant area at Granges d’Astau, there is a very basic stand-alone outdoor toilet and you’ll also find bathroom facilities at each of the refuges when they’re open. Bringing your own toilet paper and hand sanitiser is a good idea.
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