"Probably from the end of the Warring States Period, to the early Western Han Dynasty (206 BC-AD 24), they began to make their own bells with semicircular suspension loops, which imitated the style and use of those from the central regions, but also had their own unique regional features. For example, they are often decorated with animal motifs and geometric patterns that are common to their locale," says Yang.

Moreover, people's use of these bronze bells was similar to counterparts used in the Han Dynasty, working as not only musical instruments, but also as part of rituals and as a symbol of social status, he adds.

"Although the groups were remote, living on the plateau, the culture, especially bronze culture, had a close link with the Han Dynasty, and was influenced by Han culture. That paved way for the groups to become part of the country," says Yang.

Some of the artifacts reflect the "outstanding characteristics of Chinese civilization" as pointed out by President Xi Jinping, namely consistency, originality, uniformity, inclusiveness, and peacefulness, according to Guo Yanli, a professor at the Shaanxi Normal University.

She says bronze weapons vividly reflect the originality of Chinese civilization.

According to Guo, although there were various types of bronze weapons, yue axes, ge (a long pole with two blades on the end), spears and arrowheads continued to be the major types found from the early period of the Bronze Age to the time before the Qin Dynasty.