In 1947, Peshawar became part of the newly created state of Pakistan, and emerged as a cultural centre in the country's northwest. The partition of India saw the departure of many Hindko-speaking Hindus and Sikhs who held key positions in the economy of Peshawar. The University of Peshawar was established in the city in 1950, and augmented by the amalgamation of nearby British-era institutions into the university. Until the mid-1950s, Peshawar was enclosed within a city wall and sixteen gates. In the 1960s, Peshawar was a base for a CIA operation to spy on the Soviet Union, with the 1960 U-2 incident resulting in an aircraft shot down by the Soviets that flew from Peshawar. From the 1960s until the late 1970s, Peshawar was a major stop on the famous Hippie trail.