An aerial drone photo taken on Feb. 12, 2025 shows a view of downtown Nagqu, southwest China's Xizang Autonomous Region. (Xinhua/Jigme Dorje)

LHASA, May 8 (Xinhua) -- In Xizang, referred to as the "roof of the world," there exists a place called Nagqu, intriguingly dubbed the "roof of the world's roof." Averaging over 4,500 meters above sea level, the prefecture-level city in Xizang has the highest average elevation of any Chinese city.

The city proper of Nagqu is known for its rarefied atmosphere, arid climate and sandy soil, and it was once the only prefecture-level city in China without trees used for urban greening. After years of efforts, the sight of trees is no longer a luxury beyond reach in Nagqu. Various kinds of trees have survived here and are growing alongside roads. The urban greening, along with many other aspects of urban development, is improving steadily in the city.

Pregnant Tibetan antelopes migrate to their habitual birth grounds at the Qiangtang National Nature Reserve in Nyima County of Nagqu City, southwest China's Xizang Autonomous Region, May 8, 2024. (Xinhua/Tenzin Nyida)

Local villagers participate in a hand knitting competition in Shuanghu County of Nagqu City, southwest China's Xizang Autonomous Region, June 20, 2024. (Xinhua/Tenzin Nyida)

Local people enjoy Guozhuang dance in Naqqu City, southwest China's Xizang Autonomous Region, Feb. 11, 2025. (Xinhua/Jigme Dorje)

Local people plant trees in Nagqu City, southwest China's Xizang Autonomous Region, April 25, 2025. (Xinhua/Jigme Dorje)

A local villager participates in a hand knitting competition in Shuanghu County of Nagqu City, southwest China's Xizang Autonomous Region, June 20, 2024. (Xinhua/Tenzin Nyida)

Pupils plant trees in Nagqu City, southwest China's Xizang Autonomous Region, April 25, 2025. (Xinhua/Jigme Dorje)

A drone photo taken on July 12, 2022 shows early morning scenery of the countryside in Doima Township of Shuanghu County of Nagqu City, southwest China's Xizang Autonomous Region. (Xinhua/Jigme Dorje)

An aerial drone photo taken on Feb. 11, 2025 shows a view of downtown Nagqu, southwest China's Xizang Autonomous Region. (Xinhua/Jigme Dorje)

编辑：张娟