On this day, 33 years ago, on August 11, 1992 (July 13, 1992, the lunar calendar), an international expedition team confirmed the existence of a nomadic Silk Road. On August 11, 1992, a "caravan" team consisting of six Beijing jeeps and more than a dozen Russian off-road vehicles traveled more than 4000 kilometers on the muddy swamps and rugged Mongolian plateau before arriving in Ulaanbaatar and completing the inspection of the nomadic route of the Silk Road. The international expedition organized by UNESCO and the Mongolian Academy of Sciences set out from the ancient city of Kovd deep in the Altai Mountains on July 13. Carrying tents and sleeping bags, the team members followed the ancient pastoral roads and ancient post roads that used to be accessible only by horses, camels and oxcarts. They conducted a comprehensive inspection of prehistoric rock paintings scattered in the Altai Mountains, the Mongolian Desert, the Hangai Mountains and the Orkhun River Valley. The relics of ancient nomadic peoples, inscriptions, temples, ancient cities, fortresses and Tuntian sites in the Tang, Yuan and Qing Dynasties. During the inspection, scholars focused on the relationship between ancient nomadic peoples and China. In the Orkhun River Valley, the expedition team found the ruins of the capital of the Huihe Khanate built in 840 AD. The 25-square-kilometer ruins were once the capital of the largest nomadic people on the Mongolian plateau. Before that, powerful nomadic peoples such as Xiongnu, Xianbei, and Turkic had appeared on the Mongolian Plateau, but none of their capitals had been discovered. The capital of the Huitong Khanate, which was conferred by the Tang Dynasty emperor, is rectangular, with a gate, a palace gate, two moats and a square tower. Turkish scholars speculate that this ancient city may have been influenced by China's concept of "a round sky and a square earth" and the layout of the Tang Dynasty capital. What excites scholars from all over the world is that the "Guque Secret Service Monument" built by Emperor Xuanzong of the Tang Dynasty for Turkic princes in the 20th year of Kaiyuan of the Tang Dynasty still stands tall on the beautiful grassland in the Hang 'ai Mountains. The front of this marble stele, which is 3.75 meters high and 1.2 meters wide, is an inscription engraved in Tang Kai. The writing is as clear as ever. At the top of the stele is a stone carving of three dragons coiled together. The inscription records the relationship between the Tang Dynasty and the nomadic peoples in the north. Since Hangzhou 'ai Mountain does not produce marble, some scholars believe that this tall stone tablet may have been transported from inland China. The expedition team also inspected the ruins of Halahelin City located in the Orkhun River Valley. This was the capital of the Mongolian Khanate before Kublai Khan founded the Yuan Dynasty. On this ruins, China and Japanese scholars discovered a 13th century Chinese inscription "The Story of the Temple of Marquis Sanling". This inspection showed that there was indeed a nomadic Silk Road in ancient northern China that ran from Hami, Xinjiang, through the Mongolian Plateau to Liaodong. A Qing Dynasty post station map found in Kovd also clearly shows that many commercial roads start from Beijing, pass through Zhangjiakou, cross the Mongolian Plateau and enter Siberia. The expedition team traveled more than 1000 kilometers at the northern foot of the Altai Mountains to conduct a comprehensive inspection of prehistoric rock paintings. The results of special inspections show that the Altai Mountains rock paintings are an important link in the chain of rock paintings running through Eurasia and the grassland areas of northern America. They provide precious data for understanding the early activities of humans and the great migration of Eastern and Western peoples.