Nangpai Gosum, Mountain summit in Solukhumbu, Nepal and China.

Nangpai Gosum is the 7,351 m main summit of the Nangpai Gosum massif, a spur of Cho Oyu on the Nepal-China border in the Solo-Khumbu region. Its three peaks are Nangpai Gosum I (north, 7,351 m), II (middle, 7,296 m) and III (south, 7,240 m). The mountain rises as steep, ice-covered flanks with a massive pillar facing south.

A Japanese expedition made the first ascent on 12 October 1986. Two days after Katsushi Emura, Yukitoshi Endo, Katsuo Matsuki and Yoshihiro Shikoda reached the summit, six more team members followed. Nepal began issuing permits from its side in 1995, and the first ascent from Nepal came in 1996 under sirdar Ang Phurba Sherpa via the west ridge.

The official Nepali name Pasang Lhamu Chuli honours Pasang Lhamu Sherpa, the first Nepalese woman to summit Everest, who died during her descent in 1993. The mountain was given this name on the third anniversary of her death and opened for climbing at the same time.

Nepal issues climbing permits for the mountain from its side only since 1995; the first ascent from Nepal, in 1996, followed the west ridge under sirdar Ang Phurba Sherpa. Approach from the Nepalese side passes the Nangpa La, a 5,716-metre trade pass used for generations between China and Nepal. The south wall was first climbed in alpine style over five days in October 2009.

The first ascent of the south face was made by three climbers from Zermatt, Simon and Samuel Anthamatten and Michael Lerjen, between 25 and 29 October 2009. They climbed the 1550-metre route in alpine style and named it Hook or Crook, graded VI, 90 degrees, M5.