Rock art on the Helan Mountain in Ningxia Hui autonomous region, May 21, 2018. [Photo provided to chinadaily.com.cn]

There is an old, clever saying —if the "earth" goes without "art", it would be only left with "eh".

This interesting coincidence implies a boring and dull life with no art.

Thinking about times when there was no electricity nor internet, art did function as most humans' entertainment. But it could also be a tool.

For example, art on rocks was originally used as a record of life.

Such paintings, still on the Helan Mountain rage, were windows through which modern people can see the lives of ancient nomads.

Most of them came from the people living in the Spring and Autumn and Warring States periods (770-221 BC).

As the mountain spanned many provinces in Northwest China, the art on it has different themes.

Those in Ningxia Hui autonomous region mainly feature the sun god, animals, nomadic life and characters from the the Western Xia Dynasty (1038-1277).