Chile — Puerto Natales
The O Circuit in Chile's Torres del Paine National Park is a 130km, 7-10 day loop offering a profound immersion into Patagonian wilderness. This demanding route circumnavigates the iconic granite spires, traversing remote northern reaches beyond the popular W Trek. Expect rugged terrain, dramatic glacial landscapes, and unparalleled panoramas of pristine alpine wilderness.
Distance: 130.0 km
Elevation Gain: 6700 m
Difficulty: Challenging
Duration: 7-10 days
The O Circuit in Torres del Paine National Park is widely regarded as one of the most spectacular multi-day treks on the planet. Located in the deep south of Chilean Patagonia, this 130-kilometre loop encompasses the entirety of the famous "W" Trek but extends deep into the remote northern reaches of the park, offering a 360-degree circumnavigation of the Cordillera del Paine. While the W Trek provides a glimpse of the park's most famous landmarks, the O Circuit delivers a profound immersion into a landscape of glaciated mountain passes, ancient sub-antarctic forests, and the staggering expanse of the Southern Patagonian Ice Field. It is a journey that demands physical resilience, meticulous planning, and a deep respect for the volatile weather systems of the Southern Hemisphere.
Spanning between seven and ten days, the route traverses a diverse array of ecosystems. Walkers begin in the golden pampas of the eastern park boundary, climb through dense Lenga and Coihue forests, navigate the high-altitude challenge of the John Gardner Pass, and descend alongside the massive calving face of Glacier Grey. The "O" is a one-directional loop (counter-clockwise) designed to manage trail traffic and protect the fragile environment. This regulation ensures that the northern section of the trail remains a sanctuary of relative solitude, where the sound of cracking glacial ice and the wind through the southern beech trees are the primary soundtracks to your journey. For those seeking the definitive Patagonian experience, the O Circuit is the gold standard.
The O Circuit is a masterclass in geological drama. The Cordillera del Paine is a small but incredibly vertical mountain group, a tectonic uplift of granite and sedimentary rock that has been sculpted by successive ice ages into the jagged spires and deep valleys seen today. The circuit allows walkers to see every facet of this massif. The first half of the trek (the "back side") is the most remote, taking hikers away from the day-tripping crowds and into the quiet valleys of the Rio Paine. Here, the scale of the landscape becomes apparent as you walk toward the massive Southern Patagonian Ice Field—the world's second-largest contiguous extrapolar ice field.
The emotional and physical crux of the journey is the ascent of the John Gardner Pass. Standing at 1,241 metres, the pass offers a view that many hikers describe as life-changing: a seemingly infinite sea of ice stretching toward the horizon, where Glacier Grey spills from the ice field into the lake of the same name. The descent from the pass is a steep, knee-jarring transition from alpine rock and snow into lush, moss-draped rainforest. Once the route joins the "W" section at Refugio Grey, the trail becomes more social and the infrastructure more developed, but the scenery remains world-class as you enter the French Valley and finally reach the base of the iconic Las Torres (The Towers).
Patagonia is defined by its weather. The region sits in the path of the "Roaring Forties" and "Furious Fifties" winds, which can reach speeds of over 100 kilometres per hour, often carrying rain, sleet, or snow even in the height of summer. Walking the O Circuit is as much a mental challenge as a physical one; hikers must be prepared to navigate muddy trails, cross suspension bridges over roaring glacial rivers, and endure the relentless Patagonian wind. However, the reward is a sense of accomplishment and a connection to one of the last truly wild places on Earth. The infrastructure, while strictly regulated, provides a safe framework for this adventure, with designated campsites and refugios spaced at manageable intervals.
The land now known as Torres del Paine National Park has a human history stretching back thousands of years. The original inhabitants were the Aonikenk people, also known as the Tehuelche. These nomadic hunter-gatherers roamed the Patagonian pampas, following the seasonal migrations of guanacos (a relative of the llama). To the Aonikenk, the mountains were a sacred and formidable presence. The name "Paine" is derived from an indigenous word meaning "blue," a reference to the striking colour of the glacial lakes and the ice itself. European contact in the late 19th century brought devastating changes to the Aonikenk through disease and conflict with sheep ranchers, and today their legacy is primarily found in archaeological sites and the names of the landmarks.
The first recorded tourist to the area was Lady Florence Dixie, a British aristocrat and travel writer who arrived in 1879. In her book "Across Patagonia," she referred to the three granite spires as "Cleopatra's Needles." Her writings sparked international interest in the region's jagged beauty. Throughout the early 20th century, the area was primarily used for large-scale sheep farming (estancias), which led to significant deforestation as land was cleared for grazing. Recognising the unique ecological value of the landscape, the Chilean government established the Parque Nacional de Turismo Lago Grey in 1959, which was later renamed Torres del Paine National Park in 1970.
In 1978, the park was designated a UNESCO Biosphere Reserve, acknowledging its status as a global priority for conservation. The development of the O Circuit as a formal trekking route occurred much later than the W Trek, as the northern section required the construction of bridges and more robust trail management. Today, the park is managed by CONAF (Corporación Nacional Forestal), which works alongside private concessionaires to balance the high volume of international tourism with the need to protect the park's biodiversity, including the endangered South Andean Huemul (deer) and the resident puma population. The history of the park is also marked by tragedy; major forest fires in 1985, 2005, and 2011—all caused by human negligence—destroyed tens of thousands of hectares of native forest, leading to the strict "no fire" policies currently in place.
Want more background? Read extended notes on history and cultural context → Learn more
The O Circuit is only open to the public during the southern spring, summer, and early autumn (typically from 1 November to 31 March). Outside of this window, the northern section of the trail, particularly the John Gardner Pass, is covered in deep snow and becomes impassable for anyone without advanced mountaineering skills and specific winter permits. Even during the open season, the weather is the most significant factor in any trekker's experience.
Summer (December to February): This is the peak season. Days are incredibly long, with up to 18 hours of daylight, allowing for a relaxed pace. Temperatures are at their warmest, ranging from 5°C at night to 20°C during the day. However, this is also the windiest time of year. The famous Patagonian winds are most consistent in summer, capable of knocking hikers off their feet and making the crossing of the John Gardner Pass a serious undertaking. Campsites are at full capacity, and the social atmosphere is vibrant.
Shoulder Seasons (November and March): These months offer a quieter experience and are preferred by many experienced hikers. In November, the spring wildflowers are in bloom, and the mountains still hold a significant amount of snow, making for dramatic photography. March brings the spectacular autumn colours, as the Lenga forests turn vibrant shades of red and orange. The wind is generally less intense than in mid-summer, but the nights are colder, often dropping below freezing. Snow can fall at any time of year on the pass, but it is more likely in the shoulder seasons.
Weather Reality: Regardless of the month, hikers must prepare for "four seasons in one day." It is common to start a morning in bright sunshine, experience a torrential rainstorm by midday, and face sleet or snow by evening. The wind chill factor is significant; a 10°C day can feel like 0°C when the wind is blowing off the ice field. Waterproofing is not optional—it is a survival requirement. The park rangers at Campamento Los Perros will often hold hikers back and prevent them from attempting the John Gardner Pass if the wind speeds or visibility are deemed too dangerous.
Day 1: Central to Serón
Day 2: Serón to Dickson
Day 3: Dickson to Los Perros
Day 4: Los Perros to Paso (The John Gardner Pass)
Day 5: Paso to Grey
Day 6: Grey to Paine Grande
Day 7: Paine Grande to Frances/Cuernos via Valle del Francés
Day 8: Cuernos to Central via The Towers
Important Notes:
Planning the O Circuit is a logistical puzzle that must be solved months in advance. Because the trail is managed by three different entities—CONAF (the national forest service), Vertice Patagonia, and Las Torres Patagonia (formerly Fantastico Sur)—you must coordinate bookings across three separate websites. It is highly recommended to start planning at least six months before your intended start date, as the limited camping spots on the northern section sell out almost instantly when bookings open (usually in June or July).
Physical preparation is equally vital. You will be carrying a pack weighing between 12 and 18 kilograms (if camping and carrying food) over rugged, uneven terrain for 7 to 10 consecutive days. Training should include long-distance walks with a weighted pack and elevation gain. Puerto Natales is the gateway city where you will do your final preparation. It is a three-hour bus ride from Punta Arenas. In Puerto Natales, you can rent gear, buy fuel canisters (which cannot be taken on planes), and attend the daily "3 O'Clock Talk" at Erratic Rock hostel, which provides invaluable real-time trail information.
Accommodation on the O Circuit consists of a mix of Refugios (mountain hostels) and designated campsites. You are not permitted to wild camp anywhere in the park. Most sites offer the option to rent a pre-pitched tent, sleeping bag, and mat, which significantly reduces pack weight but increases cost.
Hut and Campsite Facilities:
What is NOT Provided:
Booking Requirements:
There is no single "permit" for the O Circuit; instead, your permits are your confirmed accommodation bookings. Park rangers at the Laguna Amarga entrance and at the entrance to the O-section (near Serón) will demand to see your printed or digital reservations for every single night of your trek. If you are missing even one night, you will be denied entry to the circuit.
Booking Strategy:
Park Entrance Fees:
Logistics and Transport:
Detailed route notes, maps, logistics & tips for the O Circuit Torres Del Paine (PDF).
Precisely traced GPX for the O Circuit Torres Del Paine, ready for your GPS or favourite mapping app.
If you have extra time in Torres del Paine or Puerto Natales, consider these experiences:
The John Gardner Pass: This is the most dangerous section of the trail. The weather at the pass can be radically different from the weather at Campamento Los Perros. If the wind is gusting above 80km/h, do not attempt the crossing. Rangers at Los Perros usually provide a morning briefing; listen to their advice. If you are caught in a whiteout, stay on the trail markers (orange-topped poles). Hypothermia is a genuine risk if you get wet and the wind picks up.
River Crossings and Bridges: While most major rivers have sturdy suspension bridges, smaller streams can swell rapidly during heavy rain. Use trekking poles for stability. The suspension bridges near Glacier Grey are very high and can be intimidating in high winds; cross one person at a time.
Wildlife: Pumas are present throughout the park. While they generally avoid humans, if you encounter one: do not run, make yourself look large, shout, and maintain eye contact. Guanacos are harmless but can spit if provoked. Do not leave food in your tent, as mice and foxes are common and will chew through expensive gear to reach a snack.
Health: Blisters and knee strain are the most common injuries. Address "hot spots" on your feet immediately. The descent from the pass is particularly hard on the joints; use your poles to take the weight off your knees. There is no cell service on most of the O Circuit; in an emergency, you must reach the nearest Refugio or Ranger Station. Carrying a satellite messenger (like a Garmin inReach) is highly recommended.
Mirador Británico: Located at the very end of the French Valley, this viewpoint is often skipped by tired hikers, but it is arguably the best view in the park. You are surrounded by the granite walls of the Paine Grande, the Cuernos, and the Shark's Fin. The 360-degree panorama of rock and ice is staggering.
The Suspension Bridges: Between Campamento Paso and Refugio Grey, there are three major suspension bridges. The second and third bridges offer incredible views directly down into the crevasses of the glacier's edge. They are engineering marvels in such a remote location.
Lago Dickson: Take the time to walk down to the beach at Camping Dickson. The water is filled with glacial flour, giving it a milky turquoise colour, and you can often see small icebergs that have drifted from the Dickson Glacier at the far end of the lake.
Mirador Base Las Torres: The classic "postcard" view. Most O-Circuiters visit this on their final day. For the best experience, many try to reach the towers for sunrise, when the granite glows a brilliant orange. This requires a very early start (usually 3:00 or 4:00 AM) from Camping Central or Chileno.
Torres del Paine is a fragile ecosystem under immense pressure from tourism. The "Leave No Trace" principles are not just suggestions here; they are strictly enforced by law. Chile has a zero-tolerance policy for fire in the park; lighting a fire outside of designated areas can result in immediate expulsion from the country and heavy fines or imprisonment.
Your responsibility as a walker:
