Swimming at altitude: why this experience changes your summer
Swimming in a high mountain lake is like entering another temperature in the world. The water is transparent and the landscape was sculpted by glaciers, with a silence that brings everything into order.
The cold is real: often the water is below 12-15 ºC. The shores can be slippery and, in protected areas, regulations may prohibit immersion. Read every fact sheet before deciding and prioritise safety and respect for the environment.
Near every body of water there are marked paths, viewpoints and corners for a sober, zero-waste picnic. The breeze here smells of damp rock and creeping pine after the thaw.
Bring a thin towel and footwear with good grip: they are worth more than an improvised plan. If you are looking for more mountain ideas, the guide brings together 12 fact sheets with exact location, walking access, best time, ideal public and what to do besides swimming. It includes an interactive map, practical tips, a safety checklist and a block of frequently asked questions.
How we choose these places
The lakes and lagoons on this list are, almost all of them, glacial basins above 1,000-1,500 m, in genuine mountain landscapes. We look for cold and clear waters, without conflicting uses, and we point out the beaches or designated areas when they exist.
Only bodies of water where swimming is permitted are included. When it is restricted, we indicate it and cite the regulations of the park or the town hall that regulates it.
Routes also carry weight: clear paths, realistic times and manageable elevation gains to arrive on foot. And the natural and cultural interest of each site, with its views, its fauna and its local traditions.
The information is verified with maps from the IGN, the PRUG and the PORN of the protected spaces and with the signage on-site. Safety and sustainability come first: if an area is closed or swimming is prohibited, it does not appear as an option.
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The 12 essentials to get wet at altitude with your head on straight
1. Laguna Grande de Gredos: an icy swim under Almanzor
Laguna Grande de Gredos is at about 1,940 m, under the needles of the Circo and the shadow of Almanzor (2,592 m). It is one of the classic stops for swimming at altitude, in the heart of the Sierra de Gredos (Ávila).
You arrive from the Plataforma de Gredos via a very marked cobbled path: 6.5 km one way (2-2.5 h) and 390 m of ascent elevation gain. The car park fills up quickly in summer and on weekends, so it is advisable to arrive early.
The path may be covered in snow at the beginning of summer, and in winter there may be ice and snow. The air smells of warm granite and newborn water.
The shores have boulders and night frosts occur even in summer. Avoid jumping and enter progressively. There are no lifeguards or buoys: assess the wind, do not go alone and keep your things away from shores that can rise with storms.
2. Covadonga Lakes (Enol and Ercina): Asturian high mountain with strict rules
The Enol Lakes (1,070 m) and Ercina Lakes (1,108 m) are located in the Picos de Europa, in Asturias, and can be reached by road from Cangas de Onís.
Short paths surround both lakes, with viewpoints over the hay meadows and the Picos. The best time is from June to September, due to milder weather and clear skies after storms. It is a comfortable plan for families and for travellers who combine car, bus, and gentle walks.
The air tastes of wet grass and of mist that rises slowly.
Do not swim here: swimming in the lakes is prohibited for conservation in the National Park. Check the PRUG of the Picos de Europa National Park for current details.
To get there, leave Cangas de Onís and travel 10.4 km via the AS-262 to the Covadonga Sanctuary, the starting point of the ascent via the CO-4 road. From the Real Sitio de Covadonga, it is 14.5 km to Lake Enol, with a small road towards Lake Ercina.
If you are looking to swim in mountain lakes in this area, head your dip to the pools of the Dobra river (outside the park) or check authorised areas in the municipality. Here, observe and respect.
3. Anayet Ibón: Pyrenean mirror with the Midi d’Ossau in front
The Anayet Ibón is a high mountain lake in the Tena Valley (Huesca), at about 2,230 m, with views of the silhouette of the Midi d’Ossau. It smells of heath and of black stone warmed by the high altitude sun.
The route starts from the Anayet car park (Formigal) and climbs up through the Culivillas ravine: 1.5-2 h of moderate ascent via a clear path that is damp in sections.
Couples, photographers, and ibón enthusiasts arrive at the ibón, wanting to swim in cold and crystal-clear water. In addition to swimming, you can climb to the Anayet pass, visit nearby smaller ibones, and observe meadows and peat bogs.
Enter slowly, monitor the wind, and avoid the peaty banks. During high season, camping has been prohibited since 2025.
Take everything you need and bring back your waste: the meadows are fragile and become compacted by trampling.
4. Bachimaña Ibones (Lower and Upper): electric blue over Panticosa
It is a day for hikers in good shape and for night photographers looking for dark skies.
If you have strength left, extend the route to the Upper Ibón, between peat bogs and rock polished by ice. The Bachimaña refuge serves as a resting place, and the Fraile Waterfall falls into a small nearby cirque.
The water is very cold and the banks have slabs: avoid the currents from inflows and do not approach the edge of the dam. Check the weather warnings, save your strength for the descent, and do not improvise shortcuts through scree slopes. The wind cuts the skin with a scent of mineral water and cold earth.
5. Respomuso Ibón: an accessible classic from La Sarra
The narrow valley alternates between forest and polished slabs, and smells of damp resin in the forest and hot rock on the upper ridges.
The ibón was artificially enlarged in the mid-20th century with a concrete dam. Surrounding it are the peaks of Fondellas (3071 m), Cristales (2890 m), Forqueta (2743 m), Musales (2645 m) and Balaitous (3144 m).
Go from July to September, when the snow patches have receded. The trip is suitable for hikers with time and for mountaineers linking up with Frondiellas and Balaitús. In addition to swimming, you can stroll along the shore, do some photography at sunset and observe Pyrenean chamois.
The channelled wind creates short waves. Enter sheltered areas and avoid being close to the dam. There are no strong currents in the basin, but inflows can push you; if you do not usually swim in the cold, limit swimming to short and controlled immersions.
6. Estanés Ibón: a green border between valleys and shared rules
Estanés Ibón is at 1,754 m, between Aragón and France, and has rocky shores that are comfortable for entering and exiting the water. It is a high mountain lake that you reach on foot, with the border as a backdrop.
The shortest route leaves from Sansanet, on the French side: about 1.5 h via a very busy path. From Candanchú, there are longer routes that follow the GR-11.
You can return via the Espelunguere path, descending and somewhat more exposed, but without technical difficulty. It is a plan for families with some stamina and for hikers who want a full day.
If you stay longer, do circuits through the Aspe valley and observe Alpine marmots and birds. Respect the signage on both sides of the border and the temporary restrictions. For swimming in mountain lagoons, always enter accompanied, supervise children from the shore and avoid muddy areas where the ground gives way.
7. Plan Ibón (Basa de la Mora): legend, silence and responsible swimming
Basa de la Mora is a glacial lake at 1,910 m in the Chistau Valley (Huesca), nestled between forests and limestone. It is worth the visit for its silence and its legend, that of the Moorish woman in San Juan.
You arrive via a 14 km forest track that leaves from the end of the village of Saravillo and ends at the Lavasar refuge: less than 1 h by car. The track has a toll of about 3 € per vehicle, which is paid at a machine at the start. After heavy rains, it can be impassable for normal cars due to two ravines without bridges, and a 4x4 may be needed.
From the Lavasar refuge car park, the path climbs about 150 m in elevation. The blue-green mirror smells of cold earth and resin when the sun rises behind the ridges.
There is no prepared beach, services, lifeguards, or shade.
If you swim, do so without soaps, in short immersions and far from peat bogs; if there is a prohibition sign, do not swim. In recent campaigns, people have been asked to avoid swimming due to its impact on the shores and because of the tradition of the place, so it is advisable to check the local ordinances. In addition to swimming, you can walk through the mountain pine forests and observe endemic flora.
8. High lagoons of Sierra Nevada: Yeguas and neighbours, enjoy with limitations
Above 2,800 m, in Granada, the Yeguas Lagoon and other high altitude basins of Sierra Nevada occupy a fragile high mountain environment. The lagoon extends beneath the cirque formed by Tozal del Cartujo, Tajos de La Virgen, Panderón del Veleta and Loma de Dílar.
In summer, it is surrounded by green meadows and abundant springs, because it accumulates snow for more than 5 months a year. The wind here tastes of fine ice and of creeping thyme crushed by boots.
You arrive from Hoya de la Mora via high mountain paths with accumulated elevation gain and, sometimes, snow patches well into July. You can also climb up from Collado de la Carihuela, via a steep and marked route, or from Elorrieta Refuge.
In winter, the route is not recommended, because it passes through the domains of the ski resort. It is a plan for hikers accustomed to altitude and for those who enjoy starry nights.
Before you go swimming, check the Sierra Nevada PRUG and limit immersion to the permitted areas. Do not use creams when entering and keep your distance from the borreguiles, very sensitive meadows.
In the National Park, it is forbidden to travel with motor vehicles and bicycles off the established paths, to discharge waste into springs, rivers or lagoons, and to take dogs off the lead.
9. Sanabria Lake: the great glacial bath of western Iberia
In Zamora, at about 1,000 metres altitude, the Sanabria Lake Natural Park preserves the largest lake of glacial origin in the western Iberian Peninsula.
The park brings together more than twenty lagoons, canyons of Quaternary glacial action, waterfalls and streams, with the Tera river as the main inflow and outflow of water. The water smells of damp wood and of a slow current among rushes.
July and August are the best time for a comfortable swim; in June and September the water is cool but pleasant if it is sunny. It is a plan designed for families, for those who go kayaking and for those who prefer to enter the water slowly from the shore.
In addition to swimming, you can explore the waterfalls and streams of the surroundings. Arrive early: during high season, car parks are regulated and congestion forms. Always use the designated beaches, because outside of them the shore can be fragile or restricted.
10. Small and nearby ibón: a model to discover local places calmly
In the Pyrenean and Cantabrian valleys, there are small, unnamed ibones where local bathers enter with discretion. The idea is simple: look for a secondary valley in your municipality and a track that leaves you near the start of the trail.
The usual approach takes 45-90 minutes, with 200-400 m of elevation gain via grass and rock paths. The edge of the water smells of trampled grass and of cool shade under junipers.
The best time is from July to September. Outside of that window, the water is very cold or snow patches remain. It is a plan for those seeking silence who need nothing more than a blanket and a thermos.
Verify the water quality after storms, avoid peat bogs and leave no trace of your passing.
11. Accessible lagoon near a mountain village: swimming and services at hand
Near Benasque, Cercedilla or Cangas de Onís, there are sheets of water and pools in high-altitude streams that combine nature and services. These are places you can reach by walking in a short time while keeping the village close at hand.
The marked route to the swimming area usually takes between 30 and 60 minutes from the urban centre or from a peripheral car park. A 10-15 minute drive or walk away, you have bars, a pharmacy and rural accommodation.
The best time is from June to September, and it is advisable to avoid floods after storms. It is perfect for couples and families combining rural accommodation with a quick dip.
Before entering, ask the locals about customs and seasonal restrictions: the community that looks after the site gives the best advice on how to use it properly. The air brings the smell of freshly baked bread from the village and clear water over river stones.
Check local ordinances and signs: in urban-natural swimming environments, there are often restricted areas and temporary seasonal restrictions. Additionally, you can go on guided routes, shop at the local market and birdwatch at sunset.
If you are looking for somewhere to sleep, check out this accommodation for a two-night getaway.
Interactive map: locate, filter and plan your high-altitude swim
The map brings together 10 points with quick facts: precise coordinates, altitude, approach times, elevation gains and path conditions.
The filters allow you to narrow down by what matters most on a mountain outing. You can search by accessibility according to the duration of the route: less than 2 h, between 2-4 h and more than 4 h. Also by the best time of year according to snowmelt, by difficulty (technical and physical) and by regulations (permitted, restricted, prohibited).
Each point includes a weather warning, links to official tracks or GR and PR paths where they exist, and notes on regulated car parks or shuttle buses. This way, you know before setting off if you need to book a bus seat or if the access track has specific hours.
It is advisable to consult the map the day before and on the day of your outing: snowmelt changes rhythms, the wind modifies the thermal sensation and some tracks or car parks close temporarily. Checking the regulations layer before leaving avoids doubts and fines.
How to choose your high mountain lake to swim in safely
Before looking at photos, look at the map: the real round-trip time decides if swimming is a good idea. Calculate the elevation gain, the shade on the route and how long it takes you, not the fast hiker from the review. If the route exceeds your strength, choose the nearby and well-signposted lake.
Regulations rule. Check if you are in a national, natural or municipal park: many prohibit swimming in the main body of water even if they allow getting wet in secondary streams. When in doubt, do not swim. Consult the PRUG or PORN of the area, local ordinances and the signage at the start of the route.
The path should also be checked before setting off: snow, snowfields, mud or scree can turn one hour into three. Assess the elevation gain and the maximum altitude, because above 2,000 m light altitude sickness appears if you are not used to climbing. Check the weather: afternoon storms, sustained wind of more than 30 km/h and estimated water temperature.
Think about the logistics of the day: regulated parking, shuttle buses, distance to services and mobile coverage. Adapt the outing to the group, to the level of the slowest members, to children, to animals and to less experienced swimmers.
In the water, avoid sudden entries and wet your hands, neck and chest first. Do not stray from the shore, do not jump from rocks and do not swim alone. Hypothermia can appear in minutes below 10-12 ºC: get out in time and bundle up with dry clothes when you exit.
In your backpack, a dry bag, a thin mat for sitting, a headlamp if you are pushing into the evening and a lightweight emergency blanket. If you are torn between two places, choose the one with the shortest access and clearer regulations.
Practical tips: equipment, cold and respect for the environment
The water of a high mountain lake can be just a few degrees even in August. With the right equipment and a slow entry, swimming is short and safe.
Bring a technical swimsuit, a thin thermal shirt and footwear with grippy soles; a short wetsuit is optional. Add a microfibre towel, a hat and thin gloves if you are sensitive to the cold, an insulating jacket for after the swim and a thermos with a hot drink.
Enter slowly, take a deep breath and control the gasp reflex to avoid hypothermia. If the water is below 12 ºC, limit immersion to 1-3 minutes. Get out before you start shivering, dry off, bundle up, and walk for a few minutes in the sun.
The environment rules as much as the cold. Do not use soaps or creams when swimming, because they contaminate oligotrophic waters. Stay on the paths and do not step on peat bogs or edges of amphibious vegetation. Pick up all your rubbish and also others' if you see it, and silence your music: the wildlife is nearby.
With children, maintain vigilance a few metres away and avoid deep or murky waters. If you bring a dog, leash it when regulations require it and do not take it into protected lagoons where it is prohibited. To take photographs, keep the tripod out of flooded areas and use a telephoto lens with the wildlife; do not move stones or plants to compose the shot.
End the day by shopping in the valley shop and greeting those who maintain the paths and pastures.
Frequently asked questions
Do I need a permit to swim in these lakes?
It depends on the protected area. In national parks such as Picos de Europa, swimming is usually prohibited.
Before getting into the water, consult the on-site panels and the official websites of the protected area. There you will see if swimming is permitted and in which section.
How do I avoid hypothermia in cold water?
Enter the water gradually and with controlled breathing. The first few seconds are what shock the body the most, so move slowly and without diving in all at once.
Limit immersion to a few minutes and get out as soon as you start shivering. Shivering is the signal that your body is losing heat faster than it produces it.
Out of the water, dry yourself, dress in dry layers and protect yourself from the wind. A flask with a hot drink accelerates recovery.
What do I do if I get a cramp inside?
Turn towards the nearest shore, reduce your kicking and float on your back while gently massaging the affected area. This allows the muscle to relax and gives you time to get out of the water without straining yourself.
Ask your companion for help. Swimming with someone and not straying from the shore is key to being able to receive assistance if the cramp does not subside.
Are there any totally forbidden areas?
Yes. Several lagoons in national parks and ibones of high ecological value completely restrict swimming.
Respect the signage and, if in doubt, do not swim: sanctions exist and the ecological damage is real.
When is the water "too low" in temperature?
Below 10 ºC the water is dangerous even for accustomed swimmers: physical capacity is lost quickly. Between 10 and 14 ºC it is advisable to limit yourself to short immersions.
Above 15 ºC swimming is more manageable, but the wind when getting out can chill you significantly. Bring warm clothes for afterwards and calculate your time in the water according to the temperature you measure that day.
How do I check the water quality?
In high mountains there are no daily panels with the water quality: you have to assess it on the ground. Before getting in, look at the clarity of the water and pay attention to smells.
It is also advisable to check if there are thick algae or anomalous foam, especially after a storm. Avoid swimming after heavy rains or if you see livestock concentrated very close by.
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Conclusion
A swim at altitude requires planning: choose the lake according to your available time and verify the regulations before setting off. These are places that live off silence and cold water, so respect the environment and leave everything as you found it.
Before setting off, consult the interactive map, check the weather report and decide on a plan B. If you want to extend your getaway with routes and nearby rural accommodation, explore local options and ask in the valley for current recommendations.
Share your experience and take care of these places so they remain the same on your next visit.
