Xinjiang (; ; ), officially the Xinjiang Uyghur Autonomous Region, is an autonomous region of China in the northwest of the country. It is the largest Chinese administrative division, the 8th largest country subdivision in the world, spanning over 1.6 million km². It contains the disputed territory of Aksai Chin administered by China. Xinjiang borders the countries of Mongolia, Russia, Kazakhstan, Kyrgyzstan, Tajikistan, Afghanistan, Pakistan and India. The extremely rugged Karakoram, Kunlun, and Tian Shan mountain ranges occupy much of Xinjiang's borders, as well as its western and southern regions. Xinjiang also borders Tibet Autonomous Region and the provinces of Gansu and Qinghai. The most well-known route of the historical Silk Road ran through the territory from the east to its northwestern border. In recent decades, abundant oil and mineral reserves have been found in Xinjiang, and it is currently China's largest natural gas-producing region.