In September 2016, Libor Forst, Jeff Sandifort (the head guide from Climbing South America), and I spent a week in and around Sajama National Park. We intended to climb Cerro Acotango (6,052m, 18°22'58.35"S, 69°2'51.73"W), a dormant volcano likely first ascended by Incas. It is probably one of the easiest 6,000ers in the world when climbed along the standard routes, such as the northwest ridge, the north-northeast ridge, and the west face from Chile. We decided to reach the summit by climbing the northwest face to the upper north-northeast ridge.

We reached the bottom of the face via a miners’ road and a trek up a narrow valley squeezed between two ridges. Acotango has the reputation of being an easy mountain, so we were equipped only with crampons, ice axe, and trekking poles. We didn’t even take a rope.

The face, which is covered by a receding glacier, turned out to be challenging. The lower half was a 45–55° slope full of sharp, icy penitentes, each about one meter high. Above, we followed a 2m-wide snow terrace toward the ridge before meeting overhanging rock, which we skirted by returning to the face and climbing a 50° slope covered by hard-packed snow. Above this, easy walking up the north-northeast ridge led to the summit. The face was approximately 400m high, and the ascent took us three hours.

— Roman Siegl, Czech Republic