Red, white, green, blue and black stone mosaics laid out to form a huge cross and a square have been found in Ngari, in the west of the Tibet Autonomous Region.

The relics are thought to date back to the New Stone Age some 7,000 years ago.

Zhang Jianlin, the leader of the archaeological team from Shaanxi Province, said the inlays on the ground are very beautiful. "But we don't know what these stone sketches mean," he said.

Ever since the 1920s, archaeologists have been finding numerous primitive stone formations in this no-man's land, all giving tantalizing glimpses into the lives of the prehistoric people who once inhabited the area.