Yangbajain (also spelled Yangbajing; Chinese: 羊八井; pinyin: Yángbājǐng) is a town approximately 87 kilometers (54 mi) north-west of Lhasa, halfway to Damxung in the Tibet Autonomous Region of China.

The town lies just south of the Nyainqêntanglha Mountains, in an upland lush green valley surrounded by the tents of nomads with grazing yak and sheep populating the hillside.

It is the site Yangpachen Monastery, which was historically the seat of the Shamarpas of Karma Kagyü and the Yangbajing International Cosmic Ray Observatory.

The YBJ International Cosmic Ray Observatory (羊八井国际宇宙线观测站) is located in the Yangbajing valley of the Tibetan highland, a site chosen for its high elevation at 4300 meters above sea level.

[5] Collaborating institutes includes the INFN (Istituto Nazionale di Fisica Nucleare) and various Chinese and Japanese universities.