Here's one type of art that you might see in a museum, but it's a bit tricky to transport. Rock painting has been a method of artful expression in China since ancestors painted and carved pictures on rocks to record different aspects of ancient human society. And China's rock paintings are among the most widespread and richest in the world, with some being discovered as far back as 1500 years. The Helan Mountains in north China are just one area that features a wealth of such wonders. A rock art festival and an international symposium on rock paintings opened in the region on Sunday.

Nearly 60 Chinese and overseas scholars and archaeologists attended the festival's opening ceremony. They discussed the conservation of this ancient art as well as how to decipher more of such ancient languages.

Helan Mountains are located 17 kilometers northwest of Yinchuan city, capital of north China's Ningxia Hui Autonomous Region. The mountains are more than three-thousand meters above sea level, and have traditionally served as a natural barrier offering protection from desert winds, as well as foreign invaders.

Hailed as a major wonder of ancient Chinese civilization, the rock paintings discovered in the Helan Mountains number in tens of thousands. The natural treasure spans a timeframe of over thousands of years, and stretches over hundreds of miles. The rock paintings faithfully record the natural environment and production of northern nomadic groups, revealing their social conditions, way of life, and religious beliefs.

Archaeological research in recent years has found that rock paintings are dispersed throughout the northern and southern parts of the Helan Mountains. They include portraits, totems, and signs of friendly greeting, as well as scenes of hunting, grazing, war, and dance. Experts point out there is something genuinely uninhibited and unaffected about them.