Peking University (simplified Chinese: 北京大学; traditional Chinese: 北京大學; pinyin: Běijīng Dàxué), colloquially known in Chinese as Beida (北大, Běidà), is a major research university located in Beijing, China, and a member of the C9 League. It is the first formally established modern national university of China. It was founded as Imperial Capital University in 1898 as a replacement of the ancient Guozijian (國子監 guózǐjiàn). By 1920 it had become a center for progressive thought. Today, many national and international rankings frequently place Peking University as one of the best universities in China. In addition to its academics, Peking University is especially renowned for the beauty of its traditional Chinese architecture at its campus grounds. Throughout its history, the university has distinguished itself in terms of intellectual freedom and has produced and hosted many modern and prominent Chinese thinkers, including figures such as: Lu Xun, Mao Zedong, Gu Hongming, Hu Shih, Li Dazhao, and Chen Duxiu. Peking University was influential in the birth of China's New Culture Movement, May Fourth Movement, the Tiananmen Square protest of 1989 and many other significant events.