The Niujie Mosque (simplified Chinese: 牛街礼拜寺; traditional Chinese: 牛街禮拜寺; pinyin: Niújiē lǐbàisì; Wade–Giles: Niu-chieh Li-pai-ssu "Oxen Street House of Worship" or Chinese: 牛街清真寺; pinyin: Niújiē Qīngzhēnsì; Wade–Giles: Niu-chieh Ch'ing-chen-ssu "Oxen Street Mosque") is the oldest mosque in Beijing, China. It was first built in 996 during the Liao Dynasty and was reconstructed as well as enlarged under the Kangxi Emperor (r.