Trade and goodwill between Pakistan and China are relatively strong due to the bordered Muslims area of Xinjiang, who used Pakistan as a transit to Mecca/Makkah for pilgrimage. This has been unstable after the Chinese crackdown on Xinjiang residents during Ramadan. Pakistani students often go to China to study while Chinese workers come to Pakistan to work on infrastructure projects. Pakistan ceded a portion of Kashmir in the 1960s. They also share the Karakoram Highway, one of the highest paved roads in the world. Pakistani and Chinese authorities collaborated on everything from nuclear and space technology where help was provided by China to Pakistan, to cruise missile and naval technology.