China's "Wild West" still affects relations with its western neighbors today. Early on, China's western barriers limited contact between early imperial dynasties and other Afro-Eurasian civilizations for thousands of years. What were these physical barriers?

The physical barries were: the Gobi Desert to the northwest, which made difficult the comunications between China and Mongolia, although this did not impede the Mongol conquest of China in the Middle Ages.

Another barrier to the West was the Tien Shan mountain range, which made communications between China and the Turkic nations of Central Asia difficult. In fact, nowadays, communications are still difficult between these nations.

Finally, the Tibet and the Himalayas made difficult the communications between China, and the Tibetan Kingdom, and the Indian subcontinent.