The route
The hike to Laguna 69 starts at Cebollapampa, inside Huascarán National Park, and climbs about 700 metres of elevation over 6 to 7 km to the lake, at 4,600 metres above sea level. The trail passes through queñual forests, waterfalls and high-altitude meadows before the steeper final stretch, with Chacraraju peak and Huascarán (Peru's highest, at 6,768 m) in view the whole way. Most tours run it as a full-day trip from Huaraz, leaving before dawn to make the most of the clear morning sky.
The real challenge: altitude
More than the distance, what makes this hike demanding is the altitude: you're walking between 3,900 and 4,600 metres, where the air has noticeably less oxygen than at sea level. That's why it's recommended to spend at least two or three days in Huaraz (3,050 m) first to acclimatise, drink plenty of water and skip alcohol the night before. Altitude sickness can hit even fit hikers; if severe headache, nausea or intense dizziness appear, the right call is to descend, not push on.
When to go
The dry season, May to September, offers the clearest skies and the most intense turquoise colour in the lake, fed by Chacraraju's meltwater. Outside those months rain can make the trail slippery and cover the peaks in cloud. Bring high-factor sunscreen, sunglasses and warm clothing for dawn, though midday sun at altitude can burn fast.