The Tibet Autonomous Region, officially the Xizang Autonomous Region, often shortened to Tibet or Xizang, is an autonomous region of China and is part of Southwestern China.

Xinjiang, officially the Xinjiang Uygur Autonomous Region, is an autonomous region of the People's Republic of China (PRC), located in the northwest of the country at the crossroads of Central Asia and East Asia. Being the largest province-level division of China by area and the 8th-largest country subdivision in the world, Xinjiang spans over 1.6 million square kilometres (620,000 sq mi) and has about 25 million inhabitants. Xinjiang borders the countries of Afghanistan, Kazakhstan, Kyrgyzstan, Mongolia, Pakistan, Russia, Tajikistan, and India. The rugged Karakoram, Kunlun and Tian Shan mountain ranges occupy much of Xinjiang's borders, as well as its western and southern regions. The Aksai Chin and Trans-Karakoram Tract regions are claimed by India but administered by China. Xinjiang also borders the Tibet Autonomous Region and the provinces of Gansu and Qinghai. The most well-known route of the historic Silk Road ran through the territory from the east to its northwestern border.