The Piyang and Donggar Grottoes in Ngari prefecture make up the largest Buddhist grotto complex in the Xizang autonomous region. TENZIN NYEDA/XINHUA

　　A generational transition has taken place at one of the world's highest and most remote cultural treasures.

　　Two newly trained young protectors have officially taken over fulltime guardianship of the ancient Piyang and Donggar Grottoes in the Xizang autonomous region's Ngari prefecture, following the retirement of two veteran guardians who protected the site for over three decades.

　　Champa Tsering and Rigzin Wangdrak, both 77, have stepped down as protectors of the isolated mountain haven, a role they had carried out since the early 1990s.

　　Discovered by modern archaeologists in 1992 in the rugged, far western Xizang, some 2,000 kilometers from Lhasa, the Piyang and Donggar Grottoes are the largest Buddhist grotto complex in the autonomous region. Located at over 4,000 meters above sea level, the more than 1,000 rock-cut caves date from the 10th to the 17th century. The caves served as a massive monastic community, complete with residential caves for monks, meditation chambers, ritual shrines and burial vaults.

　　For over three decades, Champa Tsering and Rigzin Wangdrak have patrolled the Piyang and Donggar Grottoes, weathering sandstorms, the harsh high-altitude climate and isolation.

　　Over time, they had become as enduring as the cliffs themselves. Now, two young figures have stepped forward to carry the baton.