This vivid blue lake surrounded by snow-covered peaks is the jewel of the Cordilleras. Set at 4600m, it's a challenging acclimatization hike (we recommend working up to it with an easier hike at altitude). 'Sixty-nine' is most commonly visited as a day trip from Huaraz and has become increasingly popular in recent years. Don't expect to have the place to yourself. Swimming in the lake is prohibited.