Lakathiya, Cordillera Real
This is the village of Lakathiya, at about 12500 feet (3800 m) high in the Cordillera Real range of the Bolivian Andes.
We spent 4 days trekking in the Cordillera Real and aimed to visit 3 mountain lakes: Laguna Illampu, Laguna Chillata, and Laguna Glacial. The route was very high, and on the first day we climbed from Sorata at 8839 feet to Laguna Illampu at 14432 feet -- an elevation gain of 5593 feet (1700 m)! At the end of the first day I was very sick due to the altitude gain; this was higher than we had trekked in the Himalaya.
The only really unfortunate aspect of the trek was that the weather was not cooperative at all: 3 out of the 4 days it was completely overcast and we could hardly see the peaks of the Illampu massif (which turned out to be right in front of us the whole time).