Plizio Visual Lab

San Martín Lake

Plizio editorial teamUpdated: Jun 2026Data Sources

Lake

Weather…

Lake San Martín, known as Lake O'Higgins in Chile, is a remote and fascinating body of water in the southern Andes. It is famous for its irregular, spider-like shape with eight deep arms cutting into the mountains. Holding the record as the deepest lake in the Americas, its depths plunge over 800 meters. The water has an almost surreal milky light-blue color caused by sediment from surrounding glaciers like the massive O'Higgins Glacier. Due to its isolated location and difficult access via the legendary Ruta 40, it remains a destination for adventurers seeking untouched wilderness and solitude. Named after the Argentine national hero José de San Martín, the lake's rugged shoreline and harsh climate have kept it one of the most sparsely populated regions in Patagonia, preserving its wild and untamed beauty.

Location: Argentina
Nearby: El Chaltén (46 km)

Best time to visit & climate

The most pleasant time to visit is Jan, Feb, Dec.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Avg °C	9	9	7	4	1	-3	-3	-1	2	4	6	8
Rain mm	29	27	32	37	51	44	35	37	22	33	33	34

📋 Practical info

🧭

Getting there

This profoundly remote Patagonian lake with its striking irregular shape is best accessed via the famous Route 40, followed by driving long, often dusty gravel roads from the town of El Calafate.

📅

Best season

The summer months from December to March represent the only realistic window for a visit, as the region becomes extremely cold, heavily snowbound, and often entirely impassable during the harsh winter.

⛰️

Terrain & paths

The environment surrounding South America's deepest lake is characterized by harsh, extremely desolate steppe landscapes and barren slopes, where developed or clearly marked trails are frequently entirely absent.

🎒

What to bring

For this remote wilderness, you absolutely need sturdy, waterproof footwear, warm protective clothing against the notoriously relentless wind, and plentiful supplies of both fresh drinking water and food.

🅿️

Parking

There are no official or paid parking lots here whatsoever. Visitors simply leave their off-road capable vehicles along the edges of the dirt tracks wherever a suitably safe and wide spot can be found.

⚠️

Safety

The absolute, profound isolation is the greatest inherent risk; mobile phone signals are practically nonexistent. Never attempt the drive without reserve fuel, a reliable spare tire, and basic survival gear.

⏱️

Time needed

Because of the incredibly long and arduous journey over the gravel roads, simply getting there and back takes massive amounts of time, making it necessary to plan for at least one full, exhausting day.