Illampú is the fourth highest mountain in Bolivia. It is located in the northern section of the Cordillera Real, part of the Andes, east of Lake Titicaca. It lies just north of the slightly higher Ancohuma, near the town of Sorata.
Despite being lower than Ancohuma, Illampú is a steeper peak, with more local relief, and it is a somewhat harder climb. In fact it has "the hardest normal route on any of the 6,000 meter peaks in Bolivia." The easiest route, by the Southwest Ridge, is rated AD (Fairly Difficult), with snow slopes up to 65 degrees. It is accessed from a high camp on the north side of the massif. The peak was first climbed on June 7, 1928 via this route, by Hans Pfann, Alfred Horeschowsky, Hugo Hörtnagel (Germans) and Erwin Hein (Austrian). Other routes include the "German Route" on the southwest face and the South Face route, both approached from the west side of the massif.