The city has hosted multiple international events, including the 1964 Summer Olympics and 1964 Summer Paralympics, the 2020 Summer Olympics and 2020 Summer Paralympics (postponed; held in 2021), and three summits of the G7 (in 1979, 1986, and 1993). Tokyo is an international research and development hub and is likewise represented by several major universities, most notably the University of Tokyo. Tokyo Station is the central hub for Japan’s high-speed railway network, the Shinkansen; Shinjuku Station in Tokyo is also the world’s busiest train station.